Masteries · Jason GlowneyArithmoí Book 1

Masteries

1.7.1 Prime Numbers and the Geometry of the Minimal Element

Pre­vi­ous­ly in this book, we in­tro­duced Cayley's the­o­rem, which states that for a group GG, there is a sym­met­ric group that acts on GG, and GG is then iso­mor­phic to a sub­group of the sym­met­ric group. In the last sec­tion, the min­i­mal el­e­ment, 𝓂ℯ\mathcal{me}, was used in the ex­pres­sion to count the number of Lie al­ge­bra gen­er­a­tors a par­tic­u­lar group had. This sec­tion will show geo­met­ri­cal­ly how Cayley's the­o­rem re­lates to the min­i­mal el­e­ment. First, we define the first four min­i­mal el­e­ments as points on the com­plex unit circle, seen in the figure below, and as fol­lows

𝓂ℯϵ=e2iπk,\mathcal{m}\mathcal{e}_{\epsilon} = e^{2i\pi k},
𝓂ℯj=e(π+2πk),\mathcal{m}\mathcal{e}_{j} = e^{(\pi + 2\pi k)},
𝓂ℯi=ei(π2+2πk),\mathcal{m}\mathcal{e}_{i} = e^{i\left( \frac{\pi}{2} + 2\pi k \right)},
𝓂ℯc=ei(π4+2πk).\begin{array}{r} \mathcal{m}\mathcal{e}_{c} = e^{i\left( \frac{\pi}{4} + 2\pi k \right)}. \end{array}
(1.7.1)
Figure
Figure 1.7.1 – Min­i­mal el­e­ments on the com­plex unit circle

On the unit circle, the min­i­mal el­e­ment, 𝓂ℯϵ=e2iπk\mathcal{m}\mathcal{e}_{\epsilon} = e^{2i\pi k}, rep­re­sents the iden­ti­ty set A{𝓂ℯϵ}A\left\{ \mathcal{m}\mathcal{e}_{\epsilon} \right\}

A(𝓂ℯϵ)={1},\begin{array}{r} A\left( \mathcal{m}\mathcal{e}_{\epsilon} \right) = \left\{ 1 \right\}, \end{array}
(1.7.2)

having one sole Lie al­ge­bra gen­er­a­tor. By ro­tat­ing iπi\pi ra­di­ans on the unit circle in either the pos­i­tive or neg­a­tive di­rec­tion, we arrive at 𝓂ℯj=ei(π+2πk)\mathcal{m}\mathcal{e}_{j} = e^{i(\pi + 2\pi k)}, which as the set of per­mu­ta­tions, A(𝓂ℯj)A\left( \mathcal{m}\mathcal{e}_{j} \right), now con­tains two Lie al­ge­bra gen­er­a­tors

A(𝓂ℯj)={−1,1},\begin{array}{r} A\left( \mathcal{m}\mathcal{e}_{j} \right) = \left\{ - 1,1 \right\}, \end{array}
(1.7.3)

which is in­clu­sive of the iden­ti­ty el­e­ment rep­re­sent­ing A(𝓂ℯϵ)A\left( \mathcal{m}\mathcal{e}_{\epsilon} \right). If we define the iden­ti­ty group G(ϵ)G(\epsilon), con­tain­ing the per­mu­ta­tion set A{𝓂ℯϵ}A\left\{ \mathcal{m}\mathcal{e}_{\epsilon} \right\}, and the split com­plex group G(j)G(j), with the per­mu­ta­tion set A(𝓂ℯj)A\left( \mathcal{m}\mathcal{e}_{j} \right), it holds that

A(𝓂ℯϵ)∈A(𝓂ℯj).\begin{array}{r} A\left( \mathcal{m}\mathcal{e}_{\epsilon} \right) \in A\left( \mathcal{m}\mathcal{e}_{j} \right). \end{array}
(1.7.4)

Since the per­mu­ta­tion A(𝓂ℯϵ)A\left( \mathcal{m}\mathcal{e}_{\epsilon} \right) set for the group G(ϵ)G(\epsilon) is on the unit circle, we can define the group G(ϵ)G(\epsilon) as

G(ϵ) ={A(𝓂ℯϵ)∈U(1,ℂ)|A(𝓂ℯϵ)∙A(𝓂ℯϵ)∗=ϵ },\begin{array}{r} G(\epsilon)\ = \left\{ A\left( \mathcal{m}\mathcal{e}_{\epsilon} \right) \in U\left( 1,\mathbb{C} \right)|A\left( \mathcal{m}\mathcal{e}_{\epsilon} \right) \bullet A\left( \mathcal{m}\mathcal{e}_{\epsilon} \right)^{*} = \epsilon\ \right\}, \end{array}
(1.7.5)

and like­wise, the group G(j)G(j), can be de­fined as

G(j) ={A(𝓂ℯj)∈U(1,ℂ)|A(𝓂ℯj)∙A(𝓂ℯj)∗=ϵ }.\begin{array}{r} G(j)\ = \left\{ A\left( \mathcal{m}\mathcal{e}_{j} \right) \in U\left( 1,\mathbb{C} \right)|A\left( \mathcal{m}\mathcal{e}_{j} \right) \bullet A\left( \mathcal{m}\mathcal{e}_{j} \right)^{*} = \epsilon\ \right\}. \end{array}
(1.7.6)

Given that G(ϵ)G(\epsilon) is de­fined by its el­e­ment in the set A(𝓂ℯϵ)A\left( \mathcal{m}\mathcal{e}_{\epsilon} \right), and A(𝓂ℯϵ)∈A(𝓂ℯj)A\left( \mathcal{m}\mathcal{e}_{\epsilon} \right) \in A\left( \mathcal{m}\mathcal{e}_{j} \right), and both sets are in the set U(1,ℂ)U\left( 1,\mathbb{C} \right)

{ A(𝓂ℯϵ),A(𝓂ℯj)}∈U(1,ℂ),\begin{array}{r} \left\{ \ A\left( \mathcal{m}\mathcal{e}_{\epsilon} \right),A\left( \mathcal{m}\mathcal{e}_{j} \right) \right\} \in U\left( 1,\mathbb{C} \right), \end{array}
(1.7.7)

it is also true that the G(ϵ)G(\epsilon) is a sub­group of G(j)G(j)

G(ϵ)∈G(j).\begin{array}{r} G(\epsilon) \in G(j). \end{array}
(1.7.8)

G(j)G(j) can be seen as the next-or­dered sym­me­try of the unit circle, which is con­sis­tent with Cayley's the­o­rem, being that the group G(ϵ)G(\epsilon) is a sub­group of the sym­me­try group G(j)G(j), based on the min­i­mal el­e­ment of choice j.j.

We can also con­sid­er the next-or­dered sym­me­try set, A(𝓂ℯj)A\left( \mathcal{m}\mathcal{e}_{j} \right), as the unions

A(𝓂ℯj)=𝓂ℯj∪A(𝓂ℯϵ)=𝓂ℯj∪𝓂ℯϵ,\begin{array}{r} A\left( \mathcal{m}\mathcal{e}_{j} \right)= \mathcal{m}\mathcal{e}_{j} \cup A\left( \mathcal{m}\mathcal{e}_{\epsilon} \right)= \mathcal{m}\mathcal{e}_{j}\cup \mathcal{m}\mathcal{e}_{\epsilon}, \end{array}
(1.7.9)

which rep­re­sents the fact A(𝓂ℯj)A\left( \mathcal{m}\mathcal{e}_{j} \right) con­tains its min­i­mal el­e­ment, and its sub­group set A(𝓂ℯϵ).A\left( \mathcal{m}\mathcal{e}_{\epsilon} \right).

We arrive at our next min­i­mal el­e­ment, 𝓂ℯi=ei(π2+2πk)=i\mathcal{m}\mathcal{e}_{i} = e^{i\left( \frac{\pi}{2} + 2\pi k \right)} = i, by ro­tat­ing iπ2\frac{i\pi}{2} ra­di­ans in the pos­i­tive di­rec­tion from 𝓂ℯϵ\mathcal{m}\mathcal{e}_{\epsilon}. The sym­me­try of the com­plex unit circle be­comes ap­par­ent, given that we could choose to rotate in­stead by iπ2\frac{i\pi}{2} ra­di­ans in the neg­a­tive di­rec­tion to arrive at −i- i. We know the circle's sym­me­try, and this sym­me­try also ap­plies to the min­i­mal el­e­ment. This is an im­por­tant con­cept, and it is re­lat­ed to the on­to­log­i­cal con­cept of net-zero. Anal­o­gous to the cyclic group, which de­fines a group con­tain­ing at least one Lie al­ge­bra gen­er­a­tor ca­pa­ble of gen­er­at­ing all el­e­ments in the set, the pos­i­tive and neg­a­tive min­i­mal el­e­ments, 𝓂ℯ±i\mathcal{m}\mathcal{e}_{\pm i}, are Lie al­ge­bra gen­er­a­tors, both of which can gen­er­ate all the el­e­ments in the A(𝓂ℯi)A\left( \mathcal{m}\mathcal{e}_{i} \right) set, shown for both cases as

i1=i,  i2=−1,  i3=−i,  i4=1,i^{1} = i,\ \ i^{2} = - 1,\ \ i^{3} = - i,\ \ i^{4} = 1,
(−i)1=−i,  (−i)2=−1,  (−i)3=i,  (−i)4=1.\begin{array}{r} ( - i)^{1} = - i,\ \ ( - i)^{2} = - 1,\ \ ( - i)^{3} = i,\ \ ( - i)^{4} = 1. \end{array}
(1.7.10)

Nested in these two ex­am­ples is the sym­me­try of the next lower order gen­er­a­tor set, A(𝓂ℯj),A\left( \mathcal{m}\mathcal{e}_{j} \right),which is rep­re­sent­ed by the sym­me­tries

i2=(−i)2=−1,  i4=(−i)4=1,\begin{array}{r} i^{2} = ( - i)^{2} = - 1,\ \ i^{4} = ( - i)^{4} = 1, \end{array}
(1.7.11)

which are the Lie gen­er­a­tors on U(1)U(1) co­in­cid­ing with the gen­er­a­tors of the A(𝓂ℯj)A\left( \mathcal{m}\mathcal{e}_{j} \right) set. By stat­ing it in these terms

i2=(−i)2=j=−1,i^{2} = ( - i)^{2} = j = - 1,
i4=(−i)4=j2=ϵ=1,\begin{array}{r} i^{4} = ( - i)^{4} = j^{2} = \epsilon = 1, \end{array}
(1.7.12)

sub­group nest­ing of the min­i­mal el­e­ment sets is ap­par­ent when con­sid­er­ing the ex­po­nents.

Next, the min­i­mal el­e­ment 𝓂ℯc=ei(π4+2πk)\mathcal{m}\mathcal{e}_{c} = e^{i\left( \frac{\pi}{4} + 2\pi k \right)} rep­re­sents a ro­ta­tion in the pos­i­tive di­rec­tion of iπ4\frac{i\pi}{4} ra­di­ans from the iden­ti­ty

𝓂ℯc=ei(π4+2πk)=(12+i2),\begin{array}{r} \mathcal{m}\mathcal{e}_{c} = e^{i\left( \frac{\pi}{4} + 2\pi k \right)} = \left( \frac{1}{\sqrt{2}} + \frac{i}{\sqrt{2}} \right), \end{array}
(1.7.13)

whose coun­ter­part ro­ta­tion in the neg­a­tive di­rec­tion, 𝓂ℯ−c\mathcal{m}\mathcal{e}_{- c}, is

𝓂ℯ−c=ei(−π4+2πk)=(12−i2).\begin{array}{r} \mathcal{m}\mathcal{e}_{- c} = e^{i\left( - \frac{\pi}{4} + 2\pi k \right)} = \left( \frac{1}{\sqrt{2}} - \frac{i}{\sqrt{2}} \right). \end{array}
(1.7.14)

Like ii and jj, we will define the pos­i­tive and neg­a­tive-valued 𝓂ℯ±c\mathcal{m}\mathcal{e}_{\pm c} as

c=(−1)14=(12+i2),−c=−(−1)34=(12−i2),\begin{array}{r} c = ( - 1)^{\frac{1}{4}} = \left( \frac{1}{\sqrt{2}} + \frac{i}{\sqrt{2}} \right), - c = {- ( - 1)}^{\frac{3}{4}} = \left( \frac{1}{\sqrt{2}} - \frac{i}{\sqrt{2}} \right), \end{array}
(1.7.15)

the vari­able choice of cc de­fines these as cone num­bers but also light, which we will con­sid­er later in the chap­ter. As was the case for 𝓂ℯ±i\mathcal{m}\mathcal{e}_{\pm i}, both Lie al­ge­bra gen­er­a­tors 𝓂ℯ±c\mathcal{m}\mathcal{e}_{\pm c}, gen­er­ate all the set's el­e­ments

c1=c,  c2=i,  c3=(−1)34,  c4=−1,c^{1} = c,\ \ c^{2} = i,\ \ c^{3} = ( - 1)^{\frac{3}{4}},\ \ c^{4} = - 1,
c5=−(−1)14,  c6=−i,  c7=−(−1)34,  c8=1,\begin{array}{r} c^{5} = - ( - 1)^{\frac{1}{4}},\ \ c^{6} = - i,\ \ c^{7} = {- ( - 1)}^{\frac{3}{4}},\ \ c^{8} = 1, \end{array}
(1.7.16)

and

(−c)1=c,  (−c)2=−i,  (−c)3=−(−1)14,  (−c)4=−1,( - c)^{1} = c,\ \ ( - c)^{2} = - i,\ \ ( - c)^{3} = {- ( - 1)}^{\frac{1}{4}},\ \ ( - c)^{4} = - 1,
(−c)5=(−1)34,  (−c)6=i,  (−c)7=(−1)14,  (−c)8=1.\begin{array}{r} ( - c)^{5} = ( - 1)^{\frac{3}{4}},\ \ ( - c)^{6} = i,\ \ ( - c)^{7} = ( - 1)^{\frac{1}{4}},\ \ ( - c)^{8} = 1. \end{array}
(1.7.17)

The nested min­i­mal el­e­ment sym­me­try equiv­a­lences for 𝓂ℯ±c\mathcal{m}\mathcal{e}_{\pm c} are

c4=(−c)4=i2=(−i)2=j=−1,c^{4} = ( - c)^{4} = i^{2} = ( - i)^{2} = j = - 1,
c8=(−c)8=i4=(−i)4=j2=ϵ=1,\begin{array}{r} c^{8} = ( - c)^{8} = i^{4} = ( - i)^{4} = j^{2} = \epsilon = 1, \end{array}
(1.7.18)

where the even ex­po­nent pat­tern that has emerged is due to our choice of sub­se­quent min­i­mal el­e­ments that are half the pre­vi­ous one. Our se­lec­tion of min­i­mal el­e­ments has led to the sym­met­ric di­vi­sion of the com­plex unit circle into small­er and small­er por­tions. The nested min­i­mal el­e­ment sym­me­try equiv­a­lences have ex­po­nents re­lat­ed by mul­ti­ples of the prime number 22. This prime number re­la­tion­ship re­lates to our ini­tial manner of sec­tion­ing the com­plex unit circle, a sym­met­ric halv­ing of suc­ces­sive sec­tions, which rep­re­sents taking suc­ces­sive square roots of the U(1)U(1) group

𝓂ℯj=(U(1))12,\mathcal{m}\mathcal{e}_{j} = \left( U(1) \right)^{\frac{1}{2}},
𝓂ℯi=(𝓂ℯj)12=((U(1))12)12=(U(1))14,\mathcal{m}\mathcal{e}_{i} = \left( \mathcal{m}\mathcal{e}_{j} \right)^{\frac{1}{2}} = \left( \left( U(1) \right)^{\frac{1}{2}} \right)^{\frac{1}{2}} = \left( U(1) \right)^{\frac{1}{4}},
𝓂ℯc=(𝓂ℯi)12=(((U(1))12)12)12=(U(1))18.\begin{array}{r} \mathcal{m}\mathcal{e}_{c} = \left( \mathcal{m}\mathcal{e}_{i} \right)^{\frac{1}{2}} = \left( \left( \left( U(1) \right)^{\frac{1}{2}} \right)^{\frac{1}{2}} \right)^{\frac{1}{2}} = \left( U(1) \right)^{\frac{1}{8}}. \end{array}
(1.7.19)

Ac­cord­ing­ly, the in­verse of the above process of these suc­ces­sive square roots is taking the square of a min­i­mal el­e­ment, which re­sults in the ad­ja­cent min­i­mal el­e­ment of a lower order, seen as fol­lows

(𝓂ℯj)2=[(U(1))12]2=𝓂ℯϵ,\left( \mathcal{m}\mathcal{e}_{j} \right)^{2} = \left\lbrack \left( U(1) \right)^{\frac{1}{2}} \right\rbrack^{2}= \mathcal{m}\mathcal{e}_{\epsilon},
(𝓂ℯi)2=[(U(1))14]2=𝓂ℯj,\left( \mathcal{m}\mathcal{e}_{i} \right)^{2} = \left\lbrack \left( U(1) \right)^{\frac{1}{4}} \right\rbrack^{2}= \mathcal{m}\mathcal{e}_{j},
(𝓂ℯc)2=[(U(1))18]2=𝓂ℯi.\begin{array}{r} \left( \mathcal{m}\mathcal{e}_{c} \right)^{2} = \left\lbrack \left( U(1) \right)^{\frac{1}{8}} \right\rbrack^{2}= \mathcal{m}\mathcal{e}_{i}. \end{array}
(1.7.20)

The number 22 is the only even prime number, and it is re­lat­ed to the ex­po­nent values for the U(1)U(1) sec­tion­ing as an ever-in­creas­ing set of min­i­mal el­e­ments, A(𝓂ℯk[1/2]),A\left( \mathcal{m}\mathcal{e}_{k\lbrack 1/2\rbrack} \right),which is based on the sec­tion­ing ratio [1/2]\lbrack 1/2\rbrack, and the kthk^{th} it­er­a­tion, which runs from 0→k0 \rightarrow k, of the min­i­mal el­e­ment

(A(𝓂ℯk[12]))(12)n={(U(1)),(U(1))12,(U(1))14,(U(1))18,(U(1))116,(U(1))132…(U(1))1n},\begin{array}{r} \left( A\left( \mathcal{m}\mathcal{e}_{k\left\lbrack \frac{1}{2} \right\rbrack} \right) \right)^{\left( \frac{1}{2} \right)^{n}} = \left\{ {\left( U(1) \right),\left( U(1) \right)}^{\frac{1}{2}},\left( U(1) \right)^{\frac{1}{4}},\left( U(1) \right)^{\frac{1}{8}},\left( U(1) \right)^{\frac{1}{16}},\left( U(1) \right)^{\frac{1}{32}}\ldots\left( U(1) \right)^{\frac{1}{n}} \right\}, \end{array}
(1.7.21)

and we note for any 𝓂ℯk[1/2]\mathcal{m}\mathcal{e}_{k\lbrack 1/2\rbrack}, we have

𝓂ℯk[12]=(U(1))(12)k.\begin{array}{r} \mathcal{m}\mathcal{e}_{k\left\lbrack \frac{1}{2} \right\rbrack} = \left( U(1) \right)^{\left( \frac{1}{2} \right)^{k}}. \end{array}
(1.7.22)

In the ex­pres­sion above, all the ex­po­nent values for the sec­tion­ing of U(1)U(1) in the set A(𝓂ℯk[1/2]),A\left( \mathcal{m}\mathcal{e}_{k\lbrack 1/2\rbrack} \right),are built upon the rec­i­p­ro­cal com­po­si­tions of the prime number 22. The min­i­mal el­e­ment 𝓂ℯk[1/2]\mathcal{m}\mathcal{e}_{k\lbrack 1/2\rbrack} with k=3k = 3, is equal to the com­po­si­tion

𝓂ℯ3[12]=(((U(1))12)12)12=(U(1))(12×12×12)=(U(1))18,\begin{array}{r} \mathcal{m}\mathcal{e}_{3\left\lbrack \frac{1}{2} \right\rbrack} = \left( \left( \left( U(1) \right)^{\frac{1}{2}} \right)^{\frac{1}{2}} \right)^{\frac{1}{2}} = \left( U(1) \right)^{\left( \frac{1}{2} \times \frac{1}{2} \times \frac{1}{2} \right)} = \left( U(1) \right)^{\frac{1}{8}}, \end{array}
(1.7.23)

which has the in­te­ger prime number com­po­si­tion coun­ter­part

2∙2∙2=8.\begin{array}{r} 2 \bullet 2 \bullet 2 = 8. \end{array}
(1.7.24)

This leads us to see that all min­i­mal el­e­ments, 𝓂ℯk[1/2],\mathcal{m}\mathcal{e}_{k\lbrack 1/2\rbrack},of the U(1)U(1) group are re­lat­ed to the rec­i­p­ro­cal prime number 12\frac{1}{2}, and its ex­po­nen­tial com­po­si­tion, except the sec­tion­ing iden­ti­ty (U(1))1\left( U(1) \right)^{1}, which is anal­o­gous to the in­te­ger number 11. The rec­i­p­ro­cal prime number 12\frac{1}{2}, should also be con­sid­ered the second el­e­ment in the har­mon­ic series, and the iden­ti­ty as the first in the series, ϵ=1\epsilon = 1.

Con­sid­er­ing the first prime number, 22, we move on to the next prime number, 33, and sec­tion U(1)U(1) into three parts, where the set of el­e­ments, A(𝓂ℯ[1/3])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack} \right), is based on the suc­ces­sive powers of min­i­mal el­e­ment 𝓂ℯ[1/3]\mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack}

A(𝓂ℯ[1/3])={(U(1))0,(U(1))13,(U(1))23},\begin{array}{r} A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack} \right) = \left\{ {\left( U(1) \right)^{0},\left( U(1) \right)}^{\frac{1}{3}},\left( U(1) \right)^{\frac{2}{3}} \right\}, \end{array}
(1.7.25)

around one ro­ta­tion of the com­plex unit circle. Each power of the min­i­mal el­e­ment 𝓂ℯk[1/3]\mathcal{m}\mathcal{e}_{k\lbrack 1/3\rbrack}, is ex­plic­it­ly

(𝓂ℯ[1/3])0=1,     (𝓂ℯ[1/3])1=e(2iπ3),      (𝓂ℯ[1/3])2=e(4iπ3),\begin{array}{r} \left( \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack} \right)^{0} = 1,\ \ \ \ \ \left( \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack} \right)^{1} = e^{\left( \frac{2i\pi}{3} \right)},\ \ \ \ \ \ \left( \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack} \right)^{2} = e^{\left( \frac{4i\pi}{3} \right)}, \end{array}
(1.7.26)

and like pre­vi­ous ex­am­ples, the di­rec­tion­al choice of ro­ta­tion away from the iden­ti­ty yields a min­i­mal el­e­ment, ±𝓂ℯ[1/3],\pm \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack},which can gen­er­ate all Lie al­ge­bras in the set. We should also note that (𝓂ℯ[1/3])2=e(4iπ3)\left( \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack} \right)^{2} = e^{\left( \frac{4i\pi}{3} \right)} also gen­er­ates all el­e­ments of the set A(𝓂ℯ[1/3])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack} \right), given that

(𝓂ℯ[13])2=(U(1))23=e(4iπ3),\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{3} \right\rbrack} \right)^{2} = \left( U(1) \right)^{\frac{2}{3}} = e^{\left( \frac{4i\pi}{3} \right)},
(𝓂ℯ[13])4=(U(1))43=(U(1))13=e(2iπ3),\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{3} \right\rbrack} \right)^{4} = \left( U(1) \right)^{\frac{4}{3}} = \left( U(1) \right)^{\frac{1}{3}} = e^{\left( \frac{2i\pi}{3} \right)},
(𝓂ℯ[13])6=(U(1))63=(U(1))1=ϵ.\begin{array}{r} \left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{3} \right\rbrack} \right)^{6} = \left( U(1) \right)^{\frac{6}{3}} = \left( U(1) \right)^{1} = \epsilon. \end{array}
(1.7.27)

We con­tin­ue the process for the fol­low­ing three min­i­mal el­e­ment sets, {A(𝓂ℯ[1/4]),A(𝓂ℯ[1/5]),A(𝓂ℯ[1/6])}\left\{ A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/4\rbrack} \right),A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/5\rbrack} \right),A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/6\rbrack} \right) \right\} which rep­re­sent the rec­i­p­ro­cal num­bers 14,15,16,\frac{1}{4},\frac{1}{5},\frac{1}{6},and along with the set A(𝓂ℯ[1/3])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack} \right), we plot each below as a poly­gon in­scribed in the com­plex unit circle, where the poly­gon ver­tices rep­re­sent the pos­i­tive­ly ori­ent­ed path the min­i­mal el­e­ment takes around the unit circle. The number of ver­tices is equiv­a­lent to the re­spec­tive num­bers 4,5,64,5,6.

Figure
Figure 1.7.2 –Prime and non-prime min­i­mal el­e­ment sets as poly­gons on the com­plex unit circle:

A(𝓂ℯ[1/3])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack} \right)(green tri­an­gle), A(𝓂ℯ[1/4])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/4\rbrack} \right)(purple square), A(𝓂ℯ[1/5])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/5\rbrack} \right)(blue pen­ta­gon), A(𝓂ℯ[1/6])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/6\rbrack} \right)(red hexa­gon).

Each poly­gon in the figure above shares the same iden­ti­ty min­i­mal el­e­ment, 𝓂ℯϵ\mathcal{m}\mathcal{e}_{\epsilon}, which is anal­o­gous to how every in­te­ger has the number 11 as a common factor. The first six in­te­gers con­tain the iden­ti­ty in­te­ger, 11, three prime num­bers, 2,3,52,3,5, and two com­pos­ite num­bers, 4,64,6. The num­bers 44 and 66 result from the fol­low­ing prime number prod­ucts

4=2×2,    6=3×2,\begin{array}{r} 4 = 2 \times 2,\ \ \ \ 6 = 3 \times 2, \end{array}
(1.7.28)

which can be fur­ther clas­si­fied as even com­pos­ite num­bers. All even com­pos­ite num­bers will be com­posed of at least one factor of the number 22, the only even prime number. The poly­gons that rep­re­sent the even com­pos­ite num­bers 44 and 66 have ver­tices at points on the unit circle, which their com­pos­ing prime num­bers have al­ready passed through. For in­stance, the set A(𝓂ℯ[1/4])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/4\rbrack} \right), rep­re­sents the com­pos­ite number 4, and shares a vertex with the prime number 22-re­lat­ed set A(𝓂ℯ[1/2])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/2\rbrack} \right), at the point (𝓂ℯ[1/2])2=𝓂ℯ[1/2]\left( \mathcal{m}\mathcal{e}_{\lbrack 1/2\rbrack} \right)^{2}= \mathcal{m}\mathcal{e}_{\lbrack 1/2\rbrack}. The set A(𝓂ℯ[1/6])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/6\rbrack} \right), rep­re­sent­ing the com­pos­ite number 66, shares ver­tices with the prime number 33-re­lat­ed set A(𝓂ℯ[1/3])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack} \right) at the points (𝓂ℯ[1/6])2=𝓂ℯ[1/3],(𝓂ℯ[1/6])4=(𝓂ℯ[1/3])2,\left( \mathcal{m}\mathcal{e}_{\lbrack 1/6\rbrack} \right)^{2}= \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack},\left( \mathcal{m}\mathcal{e}_{\lbrack 1/6\rbrack} \right)^{4} = \left( \mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack} \right)^{2},and a vertex with its other prime number re­lat­ed set A(𝓂ℯ[1/2])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/2\rbrack} \right) at (𝓂ℯ1/6)3=𝓂ℯ[1/2].\left( \mathcal{m}\mathcal{e}_{1/6} \right)^{3}= \mathcal{m}\mathcal{e}_{\lbrack 1/2\rbrack}.These shared ver­tices rep­re­sent com­pos­ite num­bers' beau­ti­ful geo­met­ric re­la­tion­ship with their prime number gen­er­a­tors in the com­plex space of the U(1)U(1) group.

The dis­tri­b­u­tion of prime num­bers is high­est in the range of the lower-valued nat­ur­al num­bers. In the set of num­bers from 11 to 100100, there are 2525 prime num­bers, 4949 even com­pos­ite num­bers, and 2525 odd com­pos­ite num­bers, the first of which is the number 9.

The radian mea­sures for the ver­tices of the first thir­teen poly­gons (n)\ (n) are shown in the table below, rep­re­sent­ing both the nthn^{th} el­e­ment of the har­mon­ic series and the nthn^{th} rec­i­p­ro­cal in­te­ger, where each nn-gon has a total of nn ver­tices, num­bered 00 to n−1n - 1.

n\displaystyle nV0\displaystyle V_{0}V1\displaystyle V_{1}V2\displaystyle V_{2}V3\displaystyle V_{3}V4\displaystyle V_{4}V5\displaystyle V_{5}V6\displaystyle V_{6}V7\displaystyle V_{7}V8\displaystyle V_{8}V9\displaystyle V_{9}V10\displaystyle V_{10}V11\displaystyle V_{11}V12\displaystyle V_{12}
1\displaystyle 1ϵ\displaystyle \epsilon
2\displaystyle 2ϵ\displaystyle \epsiloniπ\textcolor[HTML]{FF0000}{\displaystyle i\pi}
3\displaystyle 3ϵ\displaystyle \epsilon2iπ3\textcolor[HTML]{FF0000}{\displaystyle \frac{2i\pi}{3}}4iπ3\textcolor[HTML]{FF0000}{\displaystyle \frac{4i\pi}{3}}
4\displaystyle 4ϵ\displaystyle \epsiloniπ2\displaystyle \frac{i\pi}{2}iπ\textcolor[HTML]{FF0000}{\displaystyle i\pi}3iπ2\displaystyle \frac{3i\pi}{2}
5\displaystyle 5ϵ\displaystyle \epsilon2iπ5\textcolor[HTML]{FF0000}{\displaystyle \frac{2i\pi}{5}}4iπ5\textcolor[HTML]{FF0000}{\displaystyle \frac{4i\pi}{5}}6iπ5\textcolor[HTML]{FF0000}{\displaystyle \frac{6i\pi}{5}}8iπ5\textcolor[HTML]{FF0000}{\displaystyle \frac{8i\pi}{5}}
6\displaystyle 6ϵ\displaystyle \epsiloniπ3\displaystyle \frac{i\pi}{3}2iπ3\textcolor[HTML]{FF0000}{\displaystyle \frac{2i\pi}{3}}iπ\textcolor[HTML]{FF0000}{\displaystyle i\pi}4iπ3\textcolor[HTML]{FF0000}{\displaystyle \frac{4i\pi}{3}}5iπ3\displaystyle \frac{5i\pi}{3}
7\displaystyle 7ϵ\displaystyle \epsilon2iπ7\textcolor[HTML]{FF0000}{\displaystyle \frac{2i\pi}{7}}4iπ7\textcolor[HTML]{FF0000}{\displaystyle \frac{4i\pi}{7}}6iπ7\textcolor[HTML]{FF0000}{\displaystyle \frac{6i\pi}{7}}8iπ7\textcolor[HTML]{FF0000}{\displaystyle \frac{8i\pi}{7}}10iπ7\textcolor[HTML]{FF0000}{\displaystyle \frac{10i\pi}{7}}12iπ7\textcolor[HTML]{FF0000}{\displaystyle \frac{12i\pi}{7}}
8\displaystyle 8ϵ\displaystyle \epsiloniπ4\displaystyle \frac{i\pi}{4}iπ2\textcolor[HTML]{1E48FF}{\displaystyle \frac{i\pi}{2}}3iπ4\displaystyle \frac{3i\pi}{4}iπ\textcolor[HTML]{FF0000}{\displaystyle i\pi}5iπ4\displaystyle \frac{5i\pi}{4}3iπ2\textcolor[HTML]{1E48FF}{\displaystyle \frac{3i\pi}{2}}7iπ4\displaystyle \frac{7i\pi}{4}
9\displaystyle 9ϵ\displaystyle \epsilon2iπ9\displaystyle \frac{2i\pi}{9}4iπ9\displaystyle \frac{4i\pi}{9}2iπ3\textcolor[HTML]{FF0000}{\displaystyle \frac{2i\pi}{3}}8iπ9\displaystyle \frac{8i\pi}{9}10iπ9\displaystyle \frac{10i\pi}{9}4iπ3\textcolor[HTML]{FF0000}{\displaystyle \frac{4i\pi}{3}}14iπ9\displaystyle \frac{14i\pi}{9}16iπ9\displaystyle \frac{16i\pi}{9}
10\displaystyle 10ϵ\displaystyle \epsiloniπ5\displaystyle \frac{i\pi}{5}2iπ5\textcolor[HTML]{FF0000}{\displaystyle \frac{2i\pi}{5}}3iπ5\displaystyle \frac{3i\pi}{5}4iπ5\textcolor[HTML]{FF0000}{\displaystyle \frac{4i\pi}{5}}iπ\textcolor[HTML]{FF0000}{\displaystyle i\pi}6iπ5\textcolor[HTML]{FF0000}{\displaystyle \frac{6i\pi}{5}}7iπ5\displaystyle \frac{7i\pi}{5}8iπ5\textcolor[HTML]{FF0000}{\displaystyle \frac{8i\pi}{5}}9iπ5\displaystyle \frac{9i\pi}{5}
11\displaystyle 11ϵ\displaystyle \epsilon2iπ11\textcolor[HTML]{FF0000}{\displaystyle \frac{2i\pi}{11}}4iπ11\textcolor[HTML]{FF0000}{\displaystyle \frac{4i\pi}{11}}6iπ11\textcolor[HTML]{FF0000}{\displaystyle \frac{6i\pi}{11}}8iπ11\textcolor[HTML]{FF0000}{\displaystyle \frac{8i\pi}{11}}10iπ11\textcolor[HTML]{FF0000}{\displaystyle \frac{10i\pi}{11}}12iπ11\textcolor[HTML]{FF0000}{\displaystyle \frac{12i\pi}{11}}14iπ11\textcolor[HTML]{FF0000}{\displaystyle \frac{14i\pi}{11}}16iπ11\textcolor[HTML]{FF0000}{\displaystyle \frac{16i\pi}{11}}18iπ11\textcolor[HTML]{FF0000}{\displaystyle \frac{18i\pi}{11}}20iπ11\textcolor[HTML]{FF0000}{\displaystyle \frac{20i\pi}{11}}
12\displaystyle 12ϵ\displaystyle \epsiloniπ6\displaystyle \frac{i\pi}{6}iπ3\textcolor[HTML]{1E48FF}{\displaystyle \frac{i\pi}{3}}iπ2\textcolor[HTML]{1E48FF}{\displaystyle \frac{i\pi}{2}}2iπ3\textcolor[HTML]{FF0000}{\displaystyle \frac{2i\pi}{3}}5iπ6\displaystyle \frac{5i\pi}{6}iπ\textcolor[HTML]{FF0000}{\displaystyle i\pi}7iπ6\displaystyle \frac{7i\pi}{6}4iπ3\textcolor[HTML]{FF0000}{\displaystyle \frac{4i\pi}{3}}3iπ2\textcolor[HTML]{1E48FF}{\displaystyle \frac{3i\pi}{2}}5iπ3\textcolor[HTML]{1E48FF}{\displaystyle \frac{5i\pi}{3}}11iπ6\displaystyle \frac{11i\pi}{6}
13\displaystyle 13ϵ\displaystyle \epsilon2iπ13\textcolor[HTML]{FF0000}{\displaystyle \frac{2i\pi}{13}}4iπ13\textcolor[HTML]{FF0000}{\displaystyle \frac{4i\pi}{13}}6iπ13\textcolor[HTML]{FF0000}{\displaystyle \frac{6i\pi}{13}}8iπ13\textcolor[HTML]{FF0000}{\displaystyle \frac{8i\pi}{13}}10iπ13\textcolor[HTML]{FF0000}{\displaystyle \frac{10i\pi}{13}}12iπ13\textcolor[HTML]{FF0000}{\displaystyle \frac{12i\pi}{13}}14iπ13\textcolor[HTML]{FF0000}{\displaystyle \frac{14i\pi}{13}}16iπ13\textcolor[HTML]{FF0000}{\displaystyle \frac{16i\pi}{13}}18iπ13\textcolor[HTML]{FF0000}{\displaystyle \frac{18i\pi}{13}}20iπ13\textcolor[HTML]{FF0000}{\displaystyle \frac{20i\pi}{13}}22iπ13\textcolor[HTML]{FF0000}{\displaystyle \frac{22i\pi}{13}}24iπ13\textcolor[HTML]{FF0000}{\displaystyle \frac{24i\pi}{13}}
Table 1.7.1 – Ver­tices of poly­gons 11-1313 in ar­clength from 𝓂ℯϵ\mathcal{m}\mathcal{e}_{\epsilon}. Red values are prime number ver­tices, and blue values are re­peat­ing com­pound ver­tices.

In the table, re­peat­ing prime number ver­tices are sym­met­ri­cal­ly dis­trib­uted about the real-axis for each poly­gon, where, for ex­am­ple the set for the 99-gon is

9−gon={ϵ,2iπ9,4iπ9,2iπ3,8iπ9,10iπ9,4iπ3,14iπ9,16iπ9},\begin{array}{r} 9 - gon = \left\{ \epsilon,\frac{2i\pi}{9},\frac{4i\pi}{9},\frac{2i\pi}{3},\frac{8i\pi}{9},\frac{10i\pi}{9},\frac{4i\pi}{3},\frac{14i\pi}{9},\frac{16i\pi}{9} \right\}, \end{array}
(1.7.29)

where the set starts at the iden­ti­ty, then passes through two novel ver­tices, the first vertex for the geo­met­ric prime number 33, two more novel ver­tices, the second vertex for the prime number 33, and fi­nal­ly, the last two novel ver­tices. These novel ver­tices will repeat start­ing with the 1818-gon, and this can be seen best by fol­low­ing the in­te­ger pro­gres­sion for 2n2n, where start­ing at the prime number 22, all its el­e­ments repeat in 44-gon, and all its el­e­ments will then repeat in the 8,128,12-gons. The reason for this is straight­for­ward since it is re­lat­ed to re­peat­ing prime num­bers of the same value in com­pos­ite num­bers, seen by con­sid­er­ing the prime number gen­er­a­tors for each of the poly­gons

4=p1×p1,4 = p_{1} \times p_{1},
8=p1×p1×p1,8 = p_{1} \times p_{1} \times p_{1},
12=p1×p1×p2,\begin{array}{r} 12 = p_{1} \times p_{1} \times p_{2}, \end{array}
(1.7.30)

where pnp_{n} rep­re­sents the nthn^{th} prime number. We see above that the num­bers 44 and 88 are com­pound num­bers com­posed solely of the prime number p1=2p_{1} = 2, while the number 1212 is a com­pound number com­posed of two prime num­bers p1=2,p2=3p_{1} = 2,p_{2} = 3. All prime number ver­tices can be ex­pressed as

pn(V)=2iπkZk,\begin{array}{r} p_{n}(V) = \frac{2i\pi k}{Z_{k}}, \end{array}
(1.7.31)

where pnp_{n} is the nthn^{th} prime number, with an in­te­ger value ZkZ_{k}, and except for the prime number 22, is a ra­tio­nal that is always even×iπkeven \times i\pi k over odd prime

pn(V)=even×iπkpn(odd),\begin{array}{r} p_{n}(V) = \frac{even \times i\pi k}{p_{n}(odd)}, \end{array}
(1.7.32)

making them ir­re­ducible. This dif­fers from the in­te­ger num­bers, ZkZ_{k}, which will have ver­tices in two forms

Zk(V)=even×iπk Zk(odd),\begin{array}{r} Z_{k}(V) = \frac{even \times i\pi k\ }{Z_{k}(odd)}, \end{array}
(1.7.33)
Zk(V)=even×iπk Zk(even),\begin{array}{r} Z_{k}(V) = \frac{even \times i\pi k\ }{Z_{k}(even)}, \end{array}
(1.7.34)

based on whether ZkZ_{k} is an odd or even in­te­ger. Except for the number 22, when ZkZ_{k} is even, we im­me­di­ate­ly know it is a com­pound number, given it will con­tain re­ducible ra­tio­nal num­bers in its set of ver­tices. The Zk(odd)Z_{k}(odd) in­te­gers will be prime num­bers if all the ver­tices of its in­scribed nn-gon rep­re­sen­ta­tion in the unit circle are ir­re­ducible. Im­por­tant­ly, this en­ables us to geo­met­ri­cal­ly see how prime num­bers differ from com­pound num­bers since a prime number pn=Zkp_{n} = Z_{k}, will not pos­sess in­ter­nal sym­me­tries al­low­ing any lower in­te­ger-valued prime poly­gon less than pn=Zk\ {p_{n} = Z}_{k}, to rotate in a vertex-to-vertex fash­ion in the com­plex unit circle.

To show this geo­met­ric char­ac­ter­is­tic of the prime num­bers, in the fol­low­ing figure we graph the in­scribed 99-gon rep­re­sent­ing the set of ver­tices with a min­i­mal el­e­ment basis of 𝓂ℯ[1/9]\mathcal{m}\mathcal{e}_{\lbrack 1/9\rbrack}

9−gon=A(𝓂ℯ[19])={ϵ,2iπ9,2iπ9,2iπ3,8iπ9,10iπ9,4iπ3,14iπ9,16iπ9},\begin{array}{r} 9 - gon = A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{9} \right\rbrack} \right) = \left\{ \epsilon,\frac{2i\pi}{9},\frac{2i\pi}{9},\frac{2i\pi}{3},\frac{8i\pi}{9},\frac{10i\pi}{9},\frac{4i\pi}{3},\frac{14i\pi}{9},\frac{16i\pi}{9} \right\}, \end{array}
(1.7.35)

and its geo­met­ric prime number gen­er­a­tor, the equi­lat­er­al tri­an­gle, 33-gon, with a min­i­mal el­e­ment basis of 𝓂ℯ[1/3]\mathcal{m}\mathcal{e}_{\lbrack 1/3\rbrack}

3−gon=A(𝓂ℯ[13])={ϵ,2iπ3,4iπ3}.\begin{array}{r} 3 - gon = A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{3} \right\rbrack} \right) = \left\{ \epsilon,\frac{2i\pi}{3},\frac{4i\pi}{3} \right\}. \end{array}
(1.7.36)
Figure
Figure 1.7.3 – The in­scribed 99-gon rep­re­sent­ing the in­te­ger Z9Z_{9},and the

three dis­tinct ori­en­ta­tions of its prime number gen­er­a­tor P2=3P_{2} = 3.

We see the equi­lat­er­al tri­an­gle has three unique ori­en­ta­tions in the 99-gon, which is the geo­met­ric result of the number 99's com­po­si­tion

A(𝓂ℯ[19])=A((𝓂ℯ[13])13).\begin{array}{r} A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{9} \right\rbrack} \right) = A\left( \left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{3} \right\rbrack} \right)^{\frac{1}{3}} \right). \end{array}
(1.7.37)

We now have a better geo­met­ric sense of how prime num­bers can be ex­pressed in com­plex space, lead­ing us to for­mal­ly define the geo­met­ric primes.

De­f­i­n­i­tion (1.7.38) - The Geo­met­ric Primes, gpngp_{n}, are the geo­met­ric rep­re­sen­ta­tion of the prime num­bers pnp_{n} as in­scribed reg­u­lar poly­gons in the com­plex unit circle, with pnp_{n} ver­tices, VV, sym­met­ri­cal­ly arranged around the com­plex unit circle, U(1)U(1), by dis­tance in­ter­vals equal to the min­i­mal el­e­ment basis, form­ing the set of ver­tices A(𝓂ℯ[1/pn])A\left( \mathcal{m}\mathcal{e}_{\left\lbrack 1/p_{n} \right\rbrack} \right) de­fined as

A(𝓂ℯ[1/pn])={(𝓂ℯ[1pn])0,(𝓂ℯ[1pn])1,(𝓂ℯ[1pn])2,…,(𝓂ℯ[1pn])n−1},A\left( \mathcal{m}\mathcal{e}_{\left\lbrack 1/p_{n} \right\rbrack} \right) = \left\{ \left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{p_{n}} \right\rbrack} \right)^{0},\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{p_{n}} \right\rbrack} \right)^{1},\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{p_{n}} \right\rbrack} \right)^{2},\ldots,\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{p_{n}} \right\rbrack} \right)^{n - 1} \right\},

and these ver­tices have unique lo­ca­tion values for all geo­met­ric in­te­gers less than gpngp_{n}, and are unique to any geo­met­ric prime in the set of all geo­met­ric primes.

Figure
Figure 1.7.4 – The geo­met­ric prime num­bers gp1,gp2,gp3,gp4=2,3,5,7gp_{1},{gp}_{2},{gp}_{3},gp_{4} = 2,3,5,7,

in­scribed in the com­plex unit circle, rep­re­sent­ing reg­u­lar poly­gons.

Plot­ted above are the polyg­o­nal rep­re­sen­ta­tions of the first four geo­met­ric primes, gp1,gp2,gp3,gp4=2,3,5,7p_{1},{gp}_{2},{gp}_{3},{gp}_{4} = 2,3,5,7, where the number of ver­tices co­in­cides with the prime number's in­te­ger value. All ver­tices have unique lo­ca­tion values com­pared to all in­te­gers of lower value, in­clud­ing geo­met­ric primes and geo­met­ric com­pos­ites. The vertex lo­ca­tion values of all geo­met­ric primes con­tin­ue to be unique com­pared to other geo­met­ric primes in the set of all geo­met­ric primes. Com­pos­ite num­bers will share vertex values with geo­met­ric primes, given that these num­bers are com­posed of prime number prod­ucts.

The­o­rem (1.7.39) – Except for the iden­ti­ty vertex V0=𝓂ℯϵV_{0}= \mathcal{m}\mathcal{e}_{\epsilon}, all ver­tices of the geo­met­ric prime, gpngp_{n}, for n>1n > 1, can gen­er­ate all ver­tices of its in­scribed reg­u­lar nn-gon.

Proof – By de­f­i­n­i­tion, the first vertex is lo­cat­ed a dis­tance in ra­di­ans of ln⁡(𝓂ℯ[±1pn])\ln\left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right) from the iden­ti­ty vertex V0=𝓂ℯϵV_{0}= \mathcal{m}\mathcal{e}_{\epsilon}

ln⁡(𝓂ℯ[±1pn])=±2iπpn.\ln\left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right) = \pm \frac{2i\pi}{p_{n}}.

The set of pos­i­tive­ly and neg­a­tive­ly ori­ent­ed ver­tices on the bound­ary of the com­plex unit circle, with the min­i­mal el­e­ment basis 𝓂ℯ±[1pn]\mathcal{m}\mathcal{e}_{\pm \left\lbrack \frac{1}{p_{n}} \right\rbrack}, is the set

A(𝓂ℯ[±1pn])≡{(𝓂ℯ[±1pn])0,(𝓂ℯ[±1pn])1,(𝓂ℯ[±1pn])2,…,(𝓂ℯ[±1pn])pn−1} (mod 2iπ),A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right) \equiv \left\{ \left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{0},\left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{1},\left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{2},\ldots,\left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{p_{n} - 1} \right\}\ (mod\ 2i\pi),

for which each vertex is sym­met­ri­cal­ly spaced around the bound­ary of the unit circle ∈ℂ1\in \mathbb{C}^{1} by an ar­clength dis­tance, ΔV\Delta V

ΔV=±2iπpn.\Delta V = \pm \frac{2i\pi}{p_{n}}.

Given that 𝓂ℯ[1p+n ]=e(2iπpn),\mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{p + n\ } \right\rbrack} = e^{\left( \frac{2i\pi}{p_{n}} \right)}, each vertex will be lo­cat­ed at an ar­clength dis­tance from the iden­ti­ty at 𝓂ℯ[ϵ]=e2iπk\mathcal{m}\mathcal{e}_{\lbrack\epsilon\rbrack} = e^{2i\pi k} of

ΔV=±2k(iπ)pn=ln⁡[(𝓂ℯ[±1pn])k],\Delta V = \pm \frac{2k(i\pi)}{p_{n}} = \ln\left\lbrack \left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{k} \right\rbrack,

for in­te­ger values of k=0k = 0 through pn−1p_{n} - 1. There­fore, the nu­mer­a­tor re­mains even×(iπ)even \times (i\pi), the de­nom­i­na­tor is pn(odd)p_{n}(odd) for n>1n > 1, and ir­re­ducible given it is prime. The set gen­er­at­ed by a vertex lo­cat­ed at [(𝓂ℯ[±1pn])k]\left\lbrack \left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{k} \right\rbrack is

A([(𝓂ℯ[±1pn])k])={[(𝓂ℯ[±1pn])k],[(𝓂ℯ[±1pn])2k],…,[(𝓂ℯ[±1pn])pnk]},A\left( \left\lbrack \left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{k} \right\rbrack \right) = \left\{ \left\lbrack \left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{k} \right\rbrack,\left\lbrack \left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{2k} \right\rbrack,\ldots,\left\lbrack \left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{p_{n}k} \right\rbrack \right\},

which is equiv­a­lent to the set

A([(e(±2iπpn))k])={(e(±2iπpn))k,(e(±2iπpn))2k,…,(e(±2iπpn))pnk}.A\left( \left\lbrack \left( e^{\left( \pm \frac{2i\pi}{p_{n}} \right)} \right)^{k} \right\rbrack \right) = \left\{ \left( e^{\left( \pm \frac{2i\pi}{p_{n}} \right)} \right)^{k},\left( e^{\left( \pm \frac{2i\pi}{p_{n}} \right)} \right)^{2k},\ldots,\left( e^{\left( \pm \frac{2i\pi}{p_{n}} \right)} \right)^{p_{n}k} \right\}.

As the set of ver­tices A(𝓂ℯ[±1pn])A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right) is on the com­plex unit circle and de­fined as modulo 2iπ2i\pi, the set is equiv­a­lent t

A((e(±2iπpn)))={(e(±2iπpn))1,(e(±2iπpn))2,…,(e(±2iπpn))pn},A\left( \left( e^{\left( \pm \frac{2i\pi}{p_{n}} \right)} \right) \right) = \left\{ \left( e^{\left( \pm \frac{2i\pi}{p_{n}} \right)} \right)^{1},\left( e^{\left( \pm \frac{2i\pi}{p_{n}} \right)} \right)^{2},\ldots,\left( e^{\left( \pm \frac{2i\pi}{p_{n}} \right)} \right)^{p_{n}} \right\},

which can be stated as

A(𝓂ℯ[±1pn])≡{(𝓂ℯ[±1pn])0,(𝓂ℯ[±1pn])1,(𝓂ℯ[±1pn])2,…,(𝓂ℯ[±1pn])pn−1}  (mod 2iπ),A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right) \equiv \left\{ \left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{0},\left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{1},\left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{2},\ldots,\left( \mathcal{m}\mathcal{e}_{\left\lbrack \pm \frac{1}{p_{n}} \right\rbrack} \right)^{p_{n} - 1} \right\}\ \ (mod\ 2i\pi),

given that

(e(±2iπpn))pn=(e(±pn(2iπ)pn))=e±2iπ=1=(𝓂ℯ[1pn])0.\left( e^{\left( \pm \frac{2i\pi}{p_{n}} \right)} \right)^{p_{n}} = \left( e^{\left( \pm \frac{p_{n}(2i\pi)}{p_{n}} \right)} \right) = e^{\pm 2i\pi} = 1 = \left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{p_{n}} \right\rbrack} \right)^{0}.
□\square

This proof shows that the geo­met­ric primes rep­re­sent cyclic groups by the cri­te­ria that all vertex el­e­ments, except for the iden­ti­ty vertex, can gen­er­ate all vertex el­e­ments.

The prime num­bers are in­ti­mate­ly con­nect­ed to har­mon­ic series and the Rie­mann zeta func­tion, ζ(s),\zeta(s),for s∈ℂs\in \mathbb{C}, ev­i­denced by the Euler prod­uct for­mu­la

ζ(s)=∑n=1∞1ns=∏p prime11−p−s,   s∈ℂ,\begin{array}{r} \zeta(s) = \sum_{n = 1}^{\infty}{\frac{1}{n^{s}} = \prod_{p\ prime}^{}\frac{1}{1 - p^{- s}}},\ \ \ s\in \mathbb{C}, \end{array}
(1.7.40)

which was proved by Euler and pub­lished in 1737.1737.To show how Euler ar­rived at his result, we take the fol­low­ing two re­lat­ed zeta func­tion in­fi­nite series rep­re­sen­ta­tions

ζ(s)=1+12s+13s+14s+15s+16s+17s+18s+19s+110s…\zeta(s) = 1 + \frac{1}{2^{s}} + \frac{1}{3^{s}} + \frac{1}{4^{s}} + \frac{1}{5^{s}} + \frac{1}{6^{s}} + \frac{1}{7^{s}} + \frac{1}{8^{s}} + \frac{1}{9^{s}} + \frac{1}{10^{s}}\ldots
12sζ(s)=12s+14s+16s+18s+110s+112s+…,\begin{array}{r} \frac{1}{2^{s}}\zeta(s) = \frac{1}{2^{s}} + \frac{1}{4^{s}} + \frac{1}{6^{s}} + \frac{1}{8^{s}} + \frac{1}{10^{s}} + \frac{1}{12^{s}} + \ldots, \end{array}
(1.7.41)

and sub­tract the second series from the first

ζ(s)−12sζ(s)=(1−12s)ζ(s)=1+13s+15s+17s+19s….\begin{array}{r} \zeta(s) - \frac{1}{2^{s}}\zeta(s) = \left( 1 - \frac{1}{2^{s}} \right)\zeta(s) = 1 + \frac{1}{3^{s}} + \frac{1}{5^{s}} + \frac{1}{7^{s}} + \frac{1}{9^{s}}\ldots. \end{array}
(1.7.42)

Next, we take the series 13s(1−12s)ζ(s)\frac{1}{3^{s}}\left( 1 - \frac{1}{2^{s}} \right)\zeta(s)

13s(1−12s)ζ(s)=13s+19+115s+121s+127s+133s…,\begin{array}{r} \frac{1}{3^{s}}\left( 1 - \frac{1}{2^{s}} \right)\zeta(s) = \frac{1}{3^{s}} + \frac{1}{9} + \frac{1}{15^{s}} + \frac{1}{21^{s}} + \frac{1}{27^{s}} + \frac{1}{33^{s}}\ldots, \end{array}
(1.7.43)

and sub­tract this from (1−12s)ζ(s)\left( 1 - \frac{1}{2^{s}} \right)\zeta(s) to find

(1−13s)(1−12s)ζ(s)=1+15s+17s+111s+113s+117s…,\begin{array}{r} \left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{2^{s}} \right)\zeta(s) = 1 + \frac{1}{5^{s}} + \frac{1}{7^{s}} + \frac{1}{11^{s}} + \frac{1}{13^{s}} + \frac{1}{17^{s}}\ldots, \end{array}
(1.7.44)

and this is a series with all rec­i­p­ro­cal prime number fac­tors of 1/21/2 and 1/31/3 re­moved. The process re­peats in­fi­nite­ly, re­sult­ing in

…(1−113s)(1−111s)(1−17s)(1−15s)(1−13s)(1−12s)ζ(s)=1,\begin{array}{r} \ldots\left( 1 - \frac{1}{13^{s}} \right)\left( 1 - \frac{1}{11^{s}} \right)\left( 1 - \frac{1}{7^{s}} \right)\left( 1 - \frac{1}{5^{s}} \right)\left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{2^{s}} \right)\zeta(s) = 1, \end{array}
(1.7.45)

and di­vid­ing both sides by the in­fi­nite prod­uct of with terms of the form (1−1pns)\left( 1 - \frac{1}{p_{n}^{s}} \right), we find that

ζ(s)=1(1−12s)(1−13s)(1−15s)(1−17s)(1−111s)(1−113s)….\begin{array}{r} \zeta(s) = \frac{1}{\left( 1 - \frac{1}{2^{s}} \right)\left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{5^{s}} \right)\left( 1 - \frac{1}{7^{s}} \right)\left( 1 - \frac{1}{11^{s}} \right)\left( 1 - \frac{1}{13^{s}} \right)\ldots}. \end{array}
(1.7.46)

For s=1s = 1, the zeta func­tion, ζ(1),\zeta(1),simply re­duces to the har­mon­ic series

ζ(1)=1+12+13+14+15+16+17+18+19+110…,\begin{array}{r} \zeta(1) = 1 + \frac{1}{2} + \frac{1}{3} + \frac{1}{4} + \frac{1}{5} + \frac{1}{6} + \frac{1}{7} + \frac{1}{8} + \frac{1}{9} + \frac{1}{10}\ldots, \end{array}
(1.7.47)

and the Euler prod­uct is

ζ(1)=1(1−12)(1−13)(1−15)(1−17)(1−111)(1−113)….\begin{array}{r} \zeta(1) = \frac{1}{\left( 1 - \frac{1}{2} \right)\left( 1 - \frac{1}{3} \right)\left( 1 - \frac{1}{5} \right)\left( 1 - \frac{1}{7} \right)\left( 1 - \frac{1}{11} \right)\left( 1 - \frac{1}{13} \right)\ldots}. \end{array}
(1.7.48)

To show how the Euler prod­uct re­lates to geo­met­ric primes, we first look at the fol­low­ing con­tour in­te­gral

∮1z dz,   z∈ℂ.\begin{array}{r} \oint_{}^{}{\frac{1}{z}\ dz},\ \ \ z\in \mathbb{C}. \end{array}
(1.7.49)

We con­sid­er the unit circle by set­ting z(t)=eit,z(t) = e^{it},to find dzdt=ieit\frac{dz}{dt} = ie^{it}, and the in­te­gral above be­comes

∮1z dz= ∫02π1eitieit dt.\begin{array}{r} \oint_{}^{}{\frac{1}{z}\ dz} = \ \int_{0}^{2\pi}{\frac{1}{e^{it}}ie^{it}\ dt}. \end{array}
(1.7.50)

Sim­pli­fy­ing and eval­u­at­ing the in­te­gral, we find the result

∫02π1eitieit dt=∫02πi dt= it|02π=2iπ,\begin{array}{r} \int_{0}^{2\pi}{\frac{1}{e^{it}}ie^{it}\ dt = \int_{0}^{2\pi}{i\ dt} = \left. \ it \right|_{0}^{2\pi} = 2i\pi}, \end{array}
(1.7.51)

which is con­sis­tent with the perime­ter dis­tance of the com­plex unit circle in ra­di­ans. The min­i­mal el­e­ment rep­re­sents the first vertex of each nn-gon lo­cat­ed in the coun­ter­clock­wise di­rec­tion from the iden­ti­ty vertex. The perime­ter dis­tance of this vertex is

∮1Znz dz,\begin{array}{r} \oint_{}^{}{\frac{1}{Z_{n}z}\ dz}, \end{array}
(1.7.52)

where ZnZ_{n} is the rec­i­p­ro­cal in­te­ger value and 1Zn\frac{1}{Z_{n}} is the nthn^{th} el­e­ment of the har­mon­ic series. We can ex­press the zeta func­tion as a prod­uct with the pre­vi­ous con­tour in­te­gral as

∮ζ(s)z dz=2iπ1s+2iπ2s+2iπ3s+2iπ4s+2iπ5s+2iπ6s+2iπ7s+2iπ8s+2iπ9s+2iπ10s,\begin{array}{r} \oint_{}^{}{\frac{\zeta(s)}{z}\ dz} = \frac{2i\pi}{1^{s}} + \frac{2i\pi}{2^{s}} + \frac{2i\pi}{3^{s}} + \frac{2i\pi}{4^{s}} + \frac{2i\pi}{5^{s}} + \frac{2i\pi}{6^{s}} + \frac{2i\pi}{7^{s}} + \frac{2i\pi}{8^{s}} + \frac{2i\pi}{9^{s}} + \frac{2i\pi}{10^{s}}, \end{array}
(1.7.53)

which is equiv­a­lent to

∮ζ(s)z dz=∮1z dz(11s+12s+13s+14s+15s+16s+17s+18s+19s+110s…),\begin{array}{r} \oint_{}^{}{\frac{\zeta(s)}{z}\ dz} = \oint_{}^{}{\frac{1}{z}\ dz}\left( \frac{1}{1^{s}} + \frac{1}{2^{s}} + \frac{1}{3^{s}} + \frac{1}{4^{s}} + \frac{1}{5^{s}} + \frac{1}{6^{s}} + \frac{1}{7^{s}} + \frac{1}{8^{s}} + \frac{1}{9^{s}} + \frac{1}{10^{s}}\ldots \right), \end{array}
(1.7.54)

where the Euler prod­uct holds for the har­mon­ic series terms in paren­the­sis, and we can ex­press the zeta func­tion as a prod­uct with the con­tour in­te­gral of the com­plex unit circle

∮ζ(s)z dz=∮1z dz(1(1−12s)(1−13s)(1−15s)(1−17s)(1−111s)(1−113s)…).\begin{array}{r} \oint_{}^{}{\frac{\zeta(s)}{z}\ dz} = \oint_{}^{}{\frac{1}{z}\ dz}\left( \frac{1}{\left( 1 - \frac{1}{2^{s}} \right)\left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{5^{s}} \right)\left( 1 - \frac{1}{7^{s}} \right)\left( 1 - \frac{1}{11^{s}} \right)\left( 1 - \frac{1}{13^{s}} \right)\ldots} \right). \end{array}
(1.7.55)

In the last chap­ter, we con­sid­ered the series of the nat­ur­al num­bers as the el­e­ment-to-el­e­ment in­verse of the har­mon­ic series. The tri­an­gu­lar num­bers, TnT_{n}, are de­fined as the sums of suc­ces­sive se­quences of the nat­ur­al num­bers to nn, as fol­lows

Tn=∑k=1nk=1+2+3…+n.\begin{array}{r} T_{n} = \sum_{k = 1}^{n}{k = 1 + 2 + 3\ldots + n}. \end{array}
(1.7.56)

These num­bers are tri­an­gu­lar since they count ob­jects arranged in the equi­lat­er­al tri­an­gle, with one el­e­ment in each row/column po­si­tion. For ex­am­ple, the fifth tri­an­gu­lar number T5T_{5} is seen in the figure below, where T5=15T_{5} = 15 re­sults from count­ing all the white cir­cles from each row.

Figure
Figure 1.7.5 – The 5th5^{th} tri­an­gu­lar number T5=15,T_{5} = 15,and its re­la­tion­ship to the equi­lat­er­al tri­an­gle.

Eval­u­at­ing the first five tri­an­gu­lar num­bers, each rep­re­sent­ing a suc­ces­sive sum of rows from the equi­lat­er­al tri­an­gle from the figure, we find

T1=1T_{1} = 1
 T2=1+2=3\ T_{2} = 1 + 2 = 3
 T3=1+2+3=6\ T_{3} = 1 + 2 + 3 = 6
T4=1+2+3+4=10T_{4} = 1 + 2 + 3 + 4 = 10
 T5=1+2+3+4+5=15.\begin{array}{r} {\ T}_{5} = 1 + 2 + 3 + 4 + 5 = 15. \end{array}
(1.7.57)

Next, we con­sid­er how the number nn re­lates to its re­spec­tive TnT_{n} sum, by eval­u­at­ing the ratio Tnn\frac{T_{n}}{n} for each row, as fol­lows

T11=1,  T22=32,  T33=2,  T44=52,  T55=3,\begin{array}{r} \frac{T_{1}}{1} = 1,\ \ \frac{T_{2}}{2} = \frac{3}{2},\ \ \frac{T_{3}}{3} = 2,\ \ \frac{T_{4}}{4} = \frac{5}{2},\ \ \frac{T_{5}}{5} = 3, \end{array}
(1.7.58)

find­ing the dis­tinct pat­tern that each Tnn\frac{T_{n}}{n} ratio in­creas­es by 12\frac{1}{2} com­pared to Tn−1(n−1).\frac{T_{n - 1}}{(n - 1)}.This ratio gen­er­al­izes as the ex­pres­sion

Tnn=(n+1)2,\begin{array}{r} \frac{T_{n}}{n} = \frac{(n + 1)}{2}, \end{array}
(1.7.59)

where­by solv­ing for TnT_{n}, we find the tri­an­gu­lar num­bers have the closed form

Tn=n(n+1)2.\begin{array}{r} T_{n} = \frac{n(n + 1)}{2}. \end{array}
(1.7.60)

Given that a bi­no­mi­al co­ef­fi­cient is de­fined as a ratio of fac­to­ri­als

(nk)=n!(n−k)!k!,\begin{array}{r} \binom{n}{k} = \frac{n!}{(n - k)!k!}, \end{array}
(1.7.61)

the nu­mer­a­tor of TnT_{n}, can also be ex­pressed as a ratio of fac­to­ri­als

n(n+1)=(n+1)!(n−1)!,\begin{array}{r} n(n + 1) = \frac{(n + 1)!}{(n - 1)!}, \end{array}
(1.7.62)

which leads to the bi­no­mi­al co­ef­fi­cient ex­pres­sion

n(n+1)2=(n+1)!2(n−1)!=(n+1)!((n+1)−2)!2!,\begin{array}{r} \frac{n(n + 1)}{2} = \frac{(n + 1)!}{2(n - 1)!} = \frac{(n + 1)!}{\left( (n + 1) - 2 \right)!2!}, \end{array}
(1.7.63)

and the tri­an­gu­lar num­bers can be de­fined as

Tn=n(n+1)2=(n+12).\begin{array}{r} T_{n} = \frac{n(n + 1)}{2} = \binom{n + 1}{2}. \end{array}
(1.7.64)

As we found pre­vi­ous­ly, the radian dis­tance for each vertex of the ZnZ_{n} in­scribed poly­gon rep­re­sen­ta­tion in the unit circle can be ex­pressed as the min­i­mal el­e­ment re­la­tion­ship

ln⁡(A(𝓂ℯ[1n]))=ln⁡({(U(1))1n,(U(1))2n,(U(1))3n,…,(U(1))nn}),\begin{array}{r} \ln\left( A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right) \right) = \ln\left( \left\{ \left( U(1) \right)^{\frac{1}{n}},\left( U(1) \right)^{\frac{2}{n}},\left( U(1) \right)^{\frac{3}{n}},\ldots,\left( U(1) \right)^{\frac{n}{n}} \right\} \right), \end{array}
(1.7.65)

and by taking the prin­ci­pal valued log­a­rithm for each el­e­ment in the set above, we can define the set ΔV(𝓂ℯ[1/n])\Delta V\left( \mathcal{m}\mathcal{e}_{\lbrack 1/n\rbrack} \right), to rep­re­sent the set of radian dis­tance values from ϵ\epsilon, for each vertex of the ZnZ_{n} poly­gon, as

ΔV(𝓂ℯ[1n])={2iπn,4iπn,6iπn,…,2iπnn}.\begin{array}{r} \Delta V\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right) = \left\{ \frac{2i\pi}{n},\frac{4i\pi}{n},\frac{6i\pi}{n},\ldots,\frac{2i\pi n}{n} \right\}. \end{array}
(1.7.66)

Next, we choose to find the total vertex dis­tance, but sum­ming each dis­tance el­e­ment in the set ΔV(𝓂ℯ[1/n])\Delta V\left( \mathcal{m}\mathcal{e}_{\lbrack 1/n\rbrack} \right), to find the series

∑ΔV(𝓂ℯ[1n])=∑k=1n2iπkn=2iπn+4iπn+6iπn+…+2iπnn,\begin{array}{r} \sum_{}^{}{\Delta V\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right) =}\sum_{k = 1}^{n}\frac{2i\pi k}{n} = \frac{2i\pi}{n} + \frac{4i\pi}{n} + \frac{6i\pi}{n} + \ldots + \frac{2i\pi n}{n}, \end{array}
(1.7.67)

for which we factor out 2iπn\frac{2i\pi}{n}

∑ΔV(𝓂ℯ[1n])=2iπn(1+2+3+…+n),\begin{array}{r} \sum_{}^{}{\Delta V\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right) =}\frac{2i\pi}{n}(1 + 2 + 3 + \ldots + n), \end{array}
(1.7.68)

and find the pres­ence of the tri­an­gu­lar num­bers in the series. We can now sub­sti­tute our closed form for the tri­an­gu­lar num­bers into the series

2iπn(1+2+3+…+n)=2iπn(n(n+1)2)=iπ(n+1),\begin{array}{r} \frac{2i\pi}{n}(1 + 2 + 3 + \ldots + n) = \frac{2i\pi}{n}\left( \frac{n(n + 1)}{2} \right) = i\pi(n + 1), \end{array}
(1.7.69)

find­ing that our total vertex dis­tance also has a closed form as fol­lows

∑ΔV(𝓂ℯ[1n])=iπ(n+1).\begin{array}{r} \sum_{}^{}{\Delta V\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right) =}i\pi(n + 1). \end{array}
(1.7.70)

Next, we solve the series by equat­ing the tri­an­gu­lar num­bers to their fac­to­r­i­al ratio equal­i­ty, as fol­lows

2iπn(1+2+3+…+n)=2iπn((n+1)!(n−1)!2!)=iπ((n+1)!((n+1)−1)!1!)=iπ(n+11),\begin{array}{r} \frac{2i\pi}{n}(1 + 2 + 3 + \ldots + n) = \frac{2i\pi}{n}\left( \frac{(n + 1)!}{(n - 1)!2!} \right) = i\pi\left( \frac{(n + 1)!}{\left( (n + 1) - 1 \right)!1!} \right) = i\pi\binom{n + 1}{1}, \end{array}
(1.7.71)

and like­wise, we find the total vertex dis­tance sum­ma­tion re­lates to the bi­no­mi­al co­ef­fi­cient

∑ΔV(𝓂ℯ[1n])=iπ(n+11).\begin{array}{r} \sum_{}^{}{\Delta V\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right) = i\pi\binom{n + 1}{1}}. \end{array}
(1.7.72)

We return to the set A(𝓂ℯ[1/n])A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/n\rbrack} \right), which rep­re­sents the ex­po­nen­tial form for each vertex lo­ca­tion on the com­plex unit circle

A(𝓂ℯ[1n])={(U(1))1n,(U(1))2n,(U(1))3n,…,(U(1))nn},\begin{array}{r} A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right) = \left\{ \left( U(1) \right)^{\frac{1}{n}},\left( U(1) \right)^{\frac{2}{n}},\left( U(1) \right)^{\frac{3}{n}},\ldots,\left( U(1) \right)^{\frac{n}{n}} \right\}, \end{array}
(1.7.73)

which is equiv­a­lent to the form

A(𝓂ℯ[1n])={e(2iπn),e(4iπn),e(6iπn),…,e(2niπn)}.\begin{array}{r} A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right) = \left\{ e^{\left( \frac{2i\pi}{n} \right)},e^{\left( \frac{4i\pi}{n} \right)},e^{\left( \frac{6i\pi}{n} \right)},\ldots,e^{\left( \frac{2ni\pi}{n} \right)} \right\}. \end{array}
(1.7.74)

The fol­low­ing ex­po­nen­tial prod­uct sum

∏A(𝓂ℯ[1n])=∏k=1ne(2iπkn),\begin{array}{r} \prod_{}^{}{A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right)} = \prod_{k = 1}^{n}e^{\left( \frac{2i\pi k}{n} \right)}, \end{array}
(1.7.75)

is anal­o­gous to the total vertex dis­tance sum­ma­tion, and specif­i­cal­ly, they are the fol­low­ing log­a­rithm and ex­po­nen­tial re­la­tion­ships

∏A(𝓂ℯ[1n])=exp⁡(∑ΔV(𝓂ℯ[1n])),\begin{array}{r} \prod_{}^{}{A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right)} = \exp\left( \sum_{}^{}{\Delta V\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right)} \right), \end{array}
(1.7.76)

and

∑ΔV(𝓂ℯ[1n])=ln⁡(∏A(𝓂ℯ[1n])),\begin{array}{r} \sum_{}^{}{\Delta V\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right)} = \ln\left( \prod_{}^{}{A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right)} \right), \end{array}
(1.7.77)

which shows the con­nec­tion these prod­ucts and sums have with the min­i­mal el­e­ment Lie al­ge­bra. As ex­pect­ed, the result of the prod­uct sum has the ex­po­nen­tial form

∏A(𝓂ℯ[1n])=eiπ(n+1),\begin{array}{r} \prod_{}^{}{A\left( \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} \right)} = e^{i\pi(n + 1)}, \end{array}
(1.7.78)

which for in­te­ger values of nn, the value will os­cil­late be­tween −1- 1 for nn even and 11 for nn odd. Sup­pose we extend the vari­able from the nat­ur­al num­bers to the reals, n∈ℝn\in \mathbb{R}. For this case, we plot the func­tion in the figure below, find­ing the fa­mil­iar wave­forms of the ex­po­nen­tial func­tion, which are phase-shift­ed by iπi\pi ra­di­ans.

Figure
Figure 1.7.6 – The prod­uct sum plot: ∏A(𝓂ℯ[1/n])=eiπ(n+1).\prod_{}^{}{A\left( \mathcal{m}\mathcal{e}_{\lbrack 1/n\rbrack} \right)} = e^{i\pi(n + 1)}.

As we con­tin­ue study­ing the sin­gu­lar­i­ty by prob­ing deeper into it math­e­mat­i­cal­ly, the im­por­tance of tri­an­gu­lar num­bers be­comes more ap­par­ent. The exact way they are re­lat­ed to the el­e­ments of the har­mon­ic series is easy to see by start­ing with the pre­vi­ous­ly de­rived result

Tnn=(n+1)2,\begin{array}{r} \frac{T_{n}}{n} = \frac{(n + 1)}{2}, \end{array}
(1.7.79)

which we solve for 1n\frac{1}{n}, to find the in­verse re­la­tion­ship it has with the tri­an­gu­lar num­bers

1n=(n+1)2Tn,\begin{array}{r} \frac{1}{n} = \frac{(n + 1)}{2T_{n}}, \end{array}
(1.7.80)

which leads to the sum­ma­tion ex­pres­sion for the nthn^{th} har­mon­ic number as

Hn=∑k=1n1k=∑k=1n(k+1)2(1Tk).\begin{array}{r} H_{n} = \sum_{k = 1}^{n}{\frac{1}{k} = \sum_{k = 1}^{n}{\frac{(k + 1)}{2}\left( \frac{1}{T_{k}} \right).}} \end{array}
(1.7.81)

To show the beauty these num­bers have, we con­sid­er the sum­ma­tion of the in­verse tri­an­gu­lar num­bers, (𝒯n)−1,\left( \mathcal{T}_{n} \right)^{- 1},

(𝒯n)−1=∑k=1n(1Tk)=(11)+(11+13)+(11+13+16)+…(11+13+16+…1Tn),\begin{array}{r} \left( \mathcal{T}_{n} \right)^{- 1} = \sum_{k = 1}^{n}{\left( \frac{1}{T_{k}} \right) = \left( \frac{1}{1} \right) + \left( \frac{1}{1} + \frac{1}{3} \right) + \left( \frac{1}{1} + \frac{1}{3} + \frac{1}{6} \right) + \ldots\left( \frac{1}{1} + \frac{1}{3} + \frac{1}{6} + \ldots\frac{1}{T_{n}} \right),} \end{array}
(1.7.82)

which we see is a series com­posed of in­creas­ing sub­series of ra­tio­nal num­bers. To see if this series con­verges, we take each el­e­ment in the series

(Tk)−1=1Tk=1(k(k+1)2)=2k(k+1),\begin{array}{r} \left( T_{k} \right)^{- 1} = \frac{1}{T_{k}} = \frac{1}{\left( \frac{k(k + 1)}{2} \right)} = \frac{2}{k(k + 1)}, \end{array}
(1.7.83)

then take the par­tial frac­tion de­com­po­si­tion of this result to find

2k(k+1)=2k−2k+1,\begin{array}{r} \frac{2}{k(k + 1)} = \frac{2}{k} - \frac{2}{k + 1}, \end{array}
(1.7.84)

which we can now sum in­di­vid­u­al­ly to find (𝒯n)−1\left( \mathcal{T}_{n} \right)^{- 1}

(𝒯n)−1=∑k=1n(2k−2k+1)=∑k=1n2k−∑k=1n2k+1.\begin{array}{r} \left( \mathcal{T}_{n} \right)^{- 1} = \sum_{k = 1}^{n}\left( \frac{2}{k} - \frac{2}{k + 1} \right) = \sum_{k = 1}^{n}\frac{2}{k} - \sum_{k = 1}^{n}\frac{2}{k + 1}. \end{array}
(1.7.85)

Both sums are re­lat­ed to the har­mon­ic num­bers, and given that

∑k=1n1k=Hn,\begin{array}{r} \sum_{k = 1}^{n}\frac{1}{k} = H_{n}, \end{array}
(1.7.86)
−∑k=1n1k+1=−Hn+1+1,\begin{array}{r} - \sum_{k = 1}^{n}{\frac{1}{k + 1} = - H_{n + 1} + 1}, \end{array}
(1.7.87)

we can see that this series con­verges to

(𝒯n)−1=2Hn−2Hn+1+2,\begin{array}{r} \left( \mathcal{T}_{n} \right)^{- 1} = 2H_{n} - 2H_{n + 1} + 2, \end{array}
(1.7.88)

which can be sim­pli­fied as fol­lows

2(Hn−Hn+1+1)=−2n+1+22\left( H_{n} - H_{n + 1} + 1 \right) = - \frac{2}{n + 1} + 2
=2(n+1)n+1−2n+1=2nn+1,\begin{array}{r} = \frac{2(n + 1)}{n + 1} - \frac{2}{n + 1} = \frac{2n}{n + 1}, \end{array}
(1.7.89)

and there­fore, we have that

(𝒯n)−1=2nn+1.\begin{array}{r} \left( \mathcal{T}_{n} \right)^{- 1} = \frac{2n}{n + 1}. \end{array}
(1.7.90)

A beau­ti­ful thing about these num­bers is that when the sum of the (𝒯n)−1\left( \mathcal{T}_{n} \right)^{- 1} num­bers is eval­u­at­ed as n→∞n \rightarrow \infty, we find it con­verges to 2

∑k=1∞2kk+1=2.\begin{array}{r} \sum_{k = 1}^{\infty}{\frac{2k}{k + 1} = 2}. \end{array}
(1.7.91)

In­tu­itive­ly, we can see this con­ver­gence result by first look­ing at the set of suc­ces­sive values of (𝒯n)−1\left( \mathcal{T}_{n} \right)^{- 1}, A((𝒯n)−1),A\left( \left( \mathcal{T}_{n} \right)^{- 1} \right),

A((𝒯n)−1)={1,43,32,85,53,127,…},\begin{array}{r} A\left( \left( \mathcal{T}_{n} \right)^{- 1} \right) = \left\{ 1,\frac{4}{3},\frac{3}{2},\frac{8}{5},\frac{5}{3},\frac{12}{7},\ldots \right\}, \end{array}
(1.7.92)

and after fac­tor­ing out the number 2,2,we find

A((𝒯n)−1)=2×{12,23,34,45,56,67,…},\begin{array}{r} A\left( \left( \mathcal{T}_{n} \right)^{- 1} \right) = 2 \times \left\{ \frac{1}{2},\frac{2}{3},\frac{3}{4},\frac{4}{5},\frac{5}{6},\frac{6}{7},\ldots \right\}, \end{array}
(1.7.93)

where the values in the set ap­proach the value of 11, as the values of nn get larger. An ev­i­dent re­la­tion­ship exists be­tween this and the har­mon­ic series, seen when ex­press­ing the set as

A((𝒯n)−1)=2×{(1−12),(1−13),(1−14),(1−15),(1−16),(1−17),…},\begin{array}{r} A\left( \left( \mathcal{T}_{n} \right)^{- 1} \right) = 2 \times \left\{ \left( 1 - \frac{1}{2} \right),\left( 1 - \frac{1}{3} \right),\left( 1 - \frac{1}{4} \right),\left( 1 - \frac{1}{5} \right),\left( 1 - \frac{1}{6} \right),\left( 1 - \frac{1}{7} \right),\ldots \right\}, \end{array}
(1.7.94)

where each el­e­ment is now rep­re­sent­ed as a dif­fer­ence of 11 and the or­dered el­e­ments of the har­mon­ic series. This re­la­tion­ship yields the fol­low­ing par­tial sums of (𝒯n)−1\left( \mathcal{T}_{n} \right)^{- 1} num­bers, and how they relate to the har­mon­ic num­bers as

∑k=1n(𝒯k)−1=2(n+1−Hn+1),\begin{array}{r} \sum_{k = 1}^{n}\left( \mathcal{T}_{k} \right)^{- 1} = 2\left( n + 1 - H_{n + 1} \right), \end{array}
(1.7.95)

where we ar­rived at this ex­pres­sion by first con­sid­er­ing (𝒯n)−1\left( \mathcal{T}_{n} \right)^{- 1} as the series

(𝒯n)−1=∑k=1n(Tk)−1=∑k=1n112(k(k+1))=∑k=1n2(1k−1k+1),\begin{array}{r} \left( \mathcal{T}_{n} \right)^{- 1} = \sum_{k = 1}^{n}\left( T_{k} \right)^{- 1} = \sum_{k = 1}^{n}{\frac{1}{\frac{1}{2}\left( k(k + 1) \right)} =}\sum_{k = 1}^{n}{2\left( \frac{1}{k} - \frac{1}{k + 1} \right)}, \end{array}
(1.7.96)

which, when ex­pand­ed, is found to be a tele­scop­ing series

∑k=1n2(1k−1k+1)=2(1−12)+2(12−13)+2(13−14)+…+2(1n−1n+1)=2(1−1n+1).\begin{array}{r} \sum_{k = 1}^{n}{2\left( \frac{1}{k} - \frac{1}{k + 1} \right)} = 2\left( 1 - \frac{1}{2} \right) + 2\left( \frac{1}{2} - \frac{1}{3} \right) + 2\left( \frac{1}{3} - \frac{1}{4} \right) + \ldots + 2\left( \frac{1}{n} - \frac{1}{n + 1} \right) = 2\left( 1 - \frac{1}{n + 1} \right). \end{array}
(1.7.97)

There­fore, the par­tial sum of (𝒯k)−1\left( \mathcal{T}_{k} \right)^{- 1} is

∑k=1n(𝒯k)−1=∑k=1n2(1−1k+1)=2n−2(Hn+1−1)=2(n+1−Hn+1),\begin{array}{r} \sum_{k = 1}^{n}\left( \mathcal{T}_{k} \right)^{- 1} = \sum_{k = 1}^{n}{2\left( 1 - \frac{1}{k + 1} \right)} = 2n - 2\left( H_{n + 1} - 1 \right) = 2\left( n + 1 - H_{n + 1} \right), \end{array}
(1.7.98)

and after re­ar­rang­ing the ex­pres­sion by solv­ing for HnH_{n}, we find

2Hn+1=2(n+1)−∑k=1n(𝒯k)−1,\begin{array}{r} {2H}_{n + 1} = 2(n + 1) - \sum_{k = 1}^{n}\left( \mathcal{T}_{k} \right)^{- 1}, \end{array}
(1.7.99)

which sim­pli­fies to

Hn+1=(n+1)−12∑k=1n(𝒯k)−1.\begin{array}{r} H_{n + 1} = (n + 1) - \frac{1}{2}\sum_{k = 1}^{n}\left( \mathcal{T}_{k} \right)^{- 1}. \end{array}
(1.7.100)

and by de­creas­ing the it­er­a­tion for the har­mon­ic num­bers by one, this yields the fol­low­ing ex­pres­sion for HnH_{n}

Hn=n−12∑k=1n(𝒯k−1)−1.\begin{array}{r} H_{n} = n - \frac{1}{2}\sum_{k = 1}^{n}\left( \mathcal{T}_{k - 1} \right)^{- 1}. \end{array}
(1.7.101)

As we de­scribed pre­vi­ous­ly in the sec­tion, the har­mon­ic series is re­lat­ed to the prime num­bers by way of the Euler prod­uct

ζ(s)=∑n=1∞1ns=∏p prime11−p−s,   s∈ℂ,\begin{array}{r} \zeta(s) = \sum_{n = 1}^{\infty}{\frac{1}{n^{s}} = \prod_{p\ prime}^{}\frac{1}{1 - p^{- s}}},\ \ \ s\in \mathbb{C}, \end{array}
(1.7.102)

which in the case when s=1s = 1, the Rie­mann zeta func­tion ζ(1)\zeta(1) is re­lat­ed to the primes as the fol­low­ing equiv­a­lence

ζ(1)=1(1−12)(1−13)(1−15)(1−17)(1−111)(1−113)….\begin{array}{r} \zeta(1) = \frac{1}{\left( 1 - \frac{1}{2} \right)\left( 1 - \frac{1}{3} \right)\left( 1 - \frac{1}{5} \right)\left( 1 - \frac{1}{7} \right)\left( 1 - \frac{1}{11} \right)\left( 1 - \frac{1}{13} \right)\ldots}. \end{array}
(1.7.103)

Our de­fined num­bers (𝒯n)−1\left( \mathcal{T}_{n} \right)^{- 1} are re­lat­ed to the tetra­he­dral num­bers, which are de­fined as the sum­ma­tion of the tri­an­gu­lar num­bers to nn

𝒯n=∑k=1nTk=n(n+1)(n+2)6,\begin{array}{r} \mathcal{T}_{n} = \sum_{k = 1}^{n}T_{k} = \frac{n(n + 1)(n + 2)}{6}, \end{array}
(1.7.104)

with the dif­fer­ence being in the case of (𝒯n)−1\left( \mathcal{T}_{n} \right)^{- 1}, we are sum­ming the in­verse values of the tri­an­gu­lar num­bers, 1 Tk.\frac{1\ }{T_{k}}.

Our work show­ing the re­la­tion­ship be­tween the in­verse tri­an­gu­lar number sums (𝒯n)−1\left( \mathcal{T}_{n} \right)^{- 1}, the har­mon­ic series, and the har­mon­ic num­bers, HnH_{n}, lets us learn pre­cise­ly how the in­verse tri­an­gu­lar number sums (𝒯n)−1\left( \mathcal{T}_{n} \right)^{- 1} are re­lat­ed to both the Rie­mann zeta func­tion and the prime num­bers. To start, since the har­mon­ic number HnH_{n} is equal to

Hn=1+12+13+…+1n,\begin{array}{r} H_{n} = 1 + \frac{1}{2} + \frac{1}{3} + \ldots + \frac{1}{n}, \end{array}
(1.7.105)

as n→∞n \rightarrow \infty, the fol­low­ing limit is equal to the zeta func­tion, ζ(s),\zeta(s),for s=1s = 1

limn→∞⁡(Hn)=ζ(1),\begin{array}{r} {\lim_{n \rightarrow \infty}\left( H_{n} \right)} = \zeta(1), \end{array}
(1.7.106)

and based on our equal­i­ty, both of the fol­low­ing limits are equal to ζ(1)\zeta(1)

limn→∞⁡(Hn)=limn→∞⁡(n−12∑k=1n(𝒯k−1)−1)=ζ(1).\begin{array}{r} \lim_{n \rightarrow \infty}{\left( H_{n} \right) = \lim_{n \rightarrow \infty}\left( n - \frac{1}{2}\sum_{k = 1}^{n}\left( \mathcal{T}_{k - 1} \right)^{- 1} \right) = \zeta(1)}. \end{array}
(1.7.107)

Taking the ex­pres­sion found pre­vi­ous­ly for (𝒯n)−1\left( \mathcal{T}_{n} \right)^{- 1},

(𝒯n)−1=2Hn−2Hn+1+2,\begin{array}{r} \left( \mathcal{T}_{n} \right)^{- 1} = 2H_{n} - 2H_{n + 1} + 2, \end{array}
(1.7.108)

and with simple al­ge­bra­ic ma­nip­u­la­tion, we find

(𝒯n)−12=Hn−Hn+1+1,\begin{array}{r} \frac{\left( \mathcal{T}_{n} \right)^{- 1}}{2} = H_{n} - H_{n + 1} + 1, \end{array}
(1.7.109)

and given that

Hn−Hn+1=−1n+1,\begin{array}{r} H_{n} - H_{n + 1} = - \frac{1}{n + 1}, \end{array}
(1.7.110)

it is also true that

Hn−1−Hn=−1n.\begin{array}{r} H_{n - 1} - H_{n} = - \frac{1}{n}. \end{array}
(1.7.111)

This leads to the iden­ti­ty

(𝒯n−1)−12=(1−1n),\begin{array}{r} \frac{\left( \mathcal{T}_{n - 1} \right)^{- 1}}{2} = \left( 1 - \frac{1}{n} \right), \end{array}
(1.7.112)

where we note that

(𝒯0)−12=(1−11)=0.\begin{array}{r} \frac{\left( \mathcal{T}_{0} \right)^{- 1}}{2} = \left( 1 - \frac{1}{1} \right) = 0. \end{array}
(1.7.113)

Using this iden­ti­ty, we expand the limit in­volv­ing the in­verse tri­an­gu­lar number sum­ma­tion

limn→∞⁡(n−12∑k=1n(𝒯k−1)−1),\begin{array}{r} \lim_{n \rightarrow \infty}\left( n - \frac{1}{2}\sum_{k = 1}^{n}\left( \mathcal{T}_{k - 1} \right)^{- 1} \right), \end{array}
(1.7.114)

and equate it to the func­tion ζ(1)\zeta(1), to find

ζ(1)=limn→∞⁡(n)−(1−1)−(1−12)−(1−13)−(1−14)\zeta(1) = \lim_{n \rightarrow \infty}(n) - (1 - 1) - \left( 1 - \frac{1}{2} \right) - \left( 1 - \frac{1}{3} \right) - \left( 1 - \frac{1}{4} \right)
−(1−15)−(1−16)−(1−17)−…−limn→∞⁡(1−1n).\begin{array}{r} - \left( 1 - \frac{1}{5} \right) - \left( 1 - \frac{1}{6} \right) - \left( 1 - \frac{1}{7} \right) - \ldots - \lim_{n \rightarrow \infty}\left( 1 - \frac{1}{n} \right). \end{array}
(1.7.115)

In the ex­pres­sion above, thelimn→∞⁡(n)\lim_{n \rightarrow \infty}(n) is offset term-by-term by the ones in the brack­et­ed terms, while the other limit is equal to one

limn→∞⁡(1−1n)=1,\begin{array}{r} \lim_{n \rightarrow \infty}\left( 1 - \frac{1}{n} \right) = 1, \end{array}
(1.7.116)

given that

limn→∞⁡(1n)=0,\begin{array}{r} \lim_{n \rightarrow \infty}{\left( \frac{1}{n} \right) = 0,} \end{array}
(1.7.117)

which once again ver­i­fies that

 ζ(1)=limn→∞⁡(n−12∑k=1n(𝒯k−1)−1).\begin{array}{r} \ \zeta(1) = \lim_{n \rightarrow \infty}\left( n - \frac{1}{2}\sum_{k = 1}^{n}\left( \mathcal{T}_{k - 1} \right)^{- 1} \right). \end{array}
(1.7.118)

There­fore, ζ(1)\zeta(1) is equal to the fol­low­ing series of (𝒯n)−1\left( \mathcal{T}_{n} \right)^{- 1} terms

ζ(1)=limn→∞⁡(n)−12((𝒯0)−1+(𝒯1)−1+(𝒯2)−1+(𝒯3)−1+(𝒯4)−1+…+(𝒯∞−1)−1).\begin{array}{r} \zeta(1) = \lim_{n \rightarrow \infty}(n) - \frac{1}{2}\left( \left( \mathcal{T}_{0} \right)^{- 1} + \left( \mathcal{T}_{1} \right)^{- 1} + \left( \mathcal{T}_{2} \right)^{- 1} + \left( \mathcal{T}_{3} \right)^{- 1} + \left( \mathcal{T}_{4} \right)^{- 1} + \ldots + \left( \mathcal{T}_{\infty - 1} \right)^{- 1} \right). \end{array}
(1.7.119)

With the ex­pres­sion above, we see the (𝒯n)−1\left( \mathcal{T}_{n} \right)^{- 1} num­bers are re­lat­ed to the ζ(1)\zeta(1) func­tion by way of well-be­haved in­fin­i­ty minus the in­fi­nite series of the ((𝒯n)−1)2\frac{\left( \left( \mathcal{T}_{n} \right)^{- 1} \right)}{2} num­bers. To fur­ther con­sid­er a more exact re­la­tion­ship be­tween the zeta func­tion and the (𝒯n)−12\frac{\left( \mathcal{T}_{n} \right)^{- 1}}{2} num­bers, we must first define the Tau func­tion T(s)\mathrm{T}(s).

De­f­i­n­i­tion (1.7.120) – The Tau func­tion T(s)\mathrm{T}(s), for s∈ℂs\in \mathbb{C}, rep­re­sents the in­fi­nite series of the fol­low­ing in­verse tri­an­gu­lar num­bers

∑k=1n12×1Tks=(𝒯ns)−12=nsns+1=1−1ns,\sum_{k = 1}^{n}{\frac{1}{2} \times \frac{1}{T_{k}^{s}}} = \frac{\left( \mathcal{T}_{n}^{s} \right)^{- 1}}{2} = \frac{n^{s}}{n^{s} + 1} = 1 - \frac{1}{n^{s}},

for T(s)\mathrm{T}(s), de­fined as

T(s)=∑n=1∞(1−1ns),\mathrm{T}(s) = \sum_{n = 1}^{\infty}\left( 1 - \frac{1}{n^{s}} \right),

and as a series, is the el­e­ment-by-el­e­ment ad­di­tive in­verse of the re­spec­tive zeta func­tion ζ(s).\zeta(s).

It is easy to see the ad­di­tive in­verse prop­er­ty the T(s)\mathrm{T}(s) func­tion has with the zeta func­tion, given that

T(s)+ζ(s)=∑n=1∞(1−1ns)+∑n=1∞1ns=∑n=1∞1,\begin{array}{r} \mathrm{T}(s) + \zeta(s) = \sum_{n = 1}^{\infty}\left( 1 - \frac{1}{n^{s}} \right) + \sum_{n = 1}^{\infty}\frac{1}{n^{s}} = \sum_{n = 1}^{\infty}{1,} \end{array}
(1.7.121)

and we will denote the in­fin­i­ty that re­sults from the sum as n\overline{n}

∑n=1∞1=limn→∞⁡(n)=n.\begin{array}{r} \sum_{n = 1}^{\infty}{1 = \lim_{n \rightarrow \infty}(n) = \overline{n}}. \end{array}
(1.7.122)

Geo­met­ri­cal­ly, the num­bers of the T(s)\mathrm{T}(s) func­tion travel in the op­pos­i­tive di­rec­tion in the com­plex plane com­pared to the series of num­bers from the ζ(s)\zeta(s) func­tion. Specif­i­cal­ly, the num­bers are re­lat­ed as op­po­site-valued Euler prod­ucts

ζ(s)=−T(s)+n=∏p prime11−p−s,\begin{array}{r} \zeta(s) = - \mathrm{T}(s) + \overline{n} = \prod_{p\ prime}^{}\frac{1}{1 - p^{- s}}, \end{array}
(1.7.123)

which we prove for T(s)\mathrm{T}(s) in the the­o­rem that fol­lows.

The­o­rem (1.7.124) – The fol­low­ing Euler Prod­uct de­fines the Tau func­tion

T(s)=n −∏p prime11−p−s\mathrm{T}(s) = \overline{n}\ - \prod_{p\ prime}^{}\frac{1}{1 - p^{- s}}

Proof – The func­tion T(s)\mathrm{T}(s) is de­fined, for s∈ℂs\in \mathbb{C}, as the fol­low­ing sum­ma­tion

T(s)=∑n=1∞(1−1ns),\mathrm{T}(s) = \sum_{n = 1}^{\infty}\left( 1 - \frac{1}{n^{s}} \right),

which, when ex­pand­ed, is equiv­a­lent to

T(s)=(1−11s)+(1−12s)+(1−13s)+(1−14s)+(1−15s)+(1−16s)+(1−17s)+(1−18s)+…,\mathrm{T}(s) = \left( 1 - \frac{1}{1^{s}} \right) + \left( 1 - \frac{1}{2^{s}} \right) + \left( 1 - \frac{1}{3^{s}} \right) + \left( 1 - \frac{1}{4^{s}} \right) + \left( 1 - \frac{1}{5^{s}} \right) + \left( 1 - \frac{1}{6^{s}} \right) + \left( 1 - \frac{1}{7^{s}} \right) + \left( 1 - \frac{1}{8^{s}} \right) + \ldots,

this arranges to

T(s)=n−1−12s−13s−14s−15s−16s−17s−18s−…,\mathrm{T}(s) = \overline{n} - 1 - \frac{1}{2^{s}} - \frac{1}{3^{s}} - \frac{1}{4^{s}} - \frac{1}{5^{s}} - \frac{1}{6^{s}} - \frac{1}{7^{s}} - \frac{1}{8^{s}} - \ldots,

where n\overline{n} rep­re­sents the in­fi­nite sum of iden­ti­ties

n=∑n=1∞1.\overline{n} = \sum_{n = 1}^{\infty}1.

We pro­ceed to cal­cu­late (1−12s)T(s)\left( 1 - \frac{1}{2^{s}} \right)\mathrm{T}(s) by al­ge­bra­ic ma­nip­u­la­tion of the series, where we cal­cu­late first

12s×T(s)=n2s−12s−14s−16s−18s−110s−112s−114s−116s−…,\frac{1}{2^{s}} \times \mathrm{T}(s) = \frac{\overline{n}}{2^{s}} - \frac{1}{2^{s}} - \frac{1}{4^{s}} - \frac{1}{6^{s}} - \frac{1}{8^{s}} - \frac{1}{10^{s}} - \frac{1}{12^{s}} - \frac{1}{14^{s}} - \frac{1}{16^{s}} - \ldots,

and sub­tract this from T(s),\mathrm{T}(s),

(1−12s)T(s)=(n−n2s)−1−13s−15s−17s−19s−111s−…,\left( 1 - \frac{1}{2^{s}} \right)\mathrm{T}(s) = \left( \overline{n} - \frac{\overline{n}}{2^{s}} \right) - 1 - \frac{1}{3^{s}} - \frac{1}{5^{s}} - \frac{1}{7^{s}} - \frac{1}{9^{s}} - \frac{1}{11^{s}} - \ldots,

where all even-valued rec­i­p­ro­cals have can­celed, and the above sim­pli­fies to

(1−12s)T(s)=n(1−12s)−1−13s−15s−17s−19s−111s−….\left( 1 - \frac{1}{2^{s}} \right)\mathrm{T}(s) = \overline{n}\left( 1 - \frac{1}{2^{s}} \right) - 1 - \frac{1}{3^{s}} - \frac{1}{5^{s}} - \frac{1}{7^{s}} - \frac{1}{9^{s}} - \frac{1}{11^{s}} - \ldots.

We con­tin­ue this process for the sub­se­quent two it­er­a­tions as fol­lows

(1−13s)(1−12s)T(s)=(n(1−12s)−n3s(1−12s))−1−15s−17s−111s−113s−117s−…\left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{2^{s}} \right)\mathrm{T}(s) = \left( \overline{n}\left( 1 - \frac{1}{2^{s}} \right) - \frac{\overline{n}}{3^{s}}\left( 1 - \frac{1}{2^{s}} \right) \right) - 1 - \frac{1}{5^{s}} - \frac{1}{7^{s}} - \frac{1}{11^{s}} - \frac{1}{13^{s}} - \frac{1}{17^{s}} - \ldots
=(1−13s)(1−12s)T(s)=n(1−13s)(1−12s)−1−15s−17s−111s−113s−117s−…,= \left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{2^{s}} \right)\mathrm{T}(s) = \overline{n}\left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{2^{s}} \right) - 1 - \frac{1}{5^{s}} - \frac{1}{7^{s}} - \frac{1}{11^{s}} - \frac{1}{13^{s}} - \frac{1}{17^{s}} - \ldots,
(1−15s)(1−13s)(1−12s)T(s)=n(1−15s)(1−13s)(1−12s)−1−17s−111s−113s−117s−119s−…,\left( 1 - \frac{1}{5^{s}} \right)\left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{2^{s}} \right)\mathrm{T}(s) = \overline{n}\left( 1 - \frac{1}{5^{s}} \right)\left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{2^{s}} \right) - 1 - \frac{1}{7^{s}} - \frac{1}{11^{s}} - \frac{1}{13^{s}} - \frac{1}{17^{s}} - \frac{1}{19^{s}} - \ldots,

where all suc­ces­sive com­pound rec­i­p­ro­cals for the prime rec­i­p­ro­cals 3−s3^{- s} and 5−s5^{- s} have also been elim­i­nat­ed from the right-hand side. By ex­tend­ing this process in­fi­nite­ly, the result is

…(1−111s)(1−17s)(1−15s)(1−13s)(1−12s)T(s)=n[…(1−111s)(1−17s)(1−15s)(1−13s)(1−12s)]−1,\ldots\left( 1 - \frac{1}{11^{s}} \right)\left( 1 - \frac{1}{7^{s}} \right)\left( 1 - \frac{1}{5^{s}} \right)\left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{2^{s}} \right)\mathrm{T}(s) = \overline{n}\left\lbrack \ldots\left( 1 - \frac{1}{11^{s}} \right)\left( 1 - \frac{1}{7^{s}} \right)\left( 1 - \frac{1}{5^{s}} \right)\left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{2^{s}} \right) \right\rbrack - 1,

for which, fac­tor­ing and sim­pli­fi­ca­tion yields

…(1−111s)(1−17s)(1−15s)(1−13s)(1−12s)(T(s)−n)=−1,\ldots\left( 1 - \frac{1}{11^{s}} \right)\left( 1 - \frac{1}{7^{s}} \right)\left( 1 - \frac{1}{5^{s}} \right)\left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{2^{s}} \right)\left( \mathrm{T}(s) - \overline{n} \right) = - 1,

and after di­vid­ing both sides by the in­fi­nite rec­i­p­ro­cal prime-re­lat­ed prod­uct series, we find

T(s)−n=−1…(1−111s)(1−17s)(1−15s)(1−13s)(1−12s),\mathrm{T}(s) - \overline{n} = - \frac{1}{\ldots\left( 1 - \frac{1}{11^{s}} \right)\left( 1 - \frac{1}{7^{s}} \right)\left( 1 - \frac{1}{5^{s}} \right)\left( 1 - \frac{1}{3^{s}} \right)\left( 1 - \frac{1}{2^{s}} \right)},

which equals the stated the­o­rem

T(s)=n −∏p prime11−p−s.\mathrm{T}(s) = \overline{n}\ - \prod_{p\ prime}^{}\frac{1}{1 - p^{- s}}.
 □\begin{array}{r} \ \square \end{array}

Pre­vi­ous­ly, we ar­rived at the equal­i­ty for ζ(1)\zeta(1)

ζ(1)=limn→∞⁡(n)−12((𝒯1)−1+(𝒯2)−1+(𝒯3)−1+(𝒯4)−1+…+(𝒯∞)−1).\begin{array}{r} \zeta(1) = \lim_{n \rightarrow \infty}(n) - \frac{1}{2}\left( \left( \mathcal{T}_{1} \right)^{- 1} + \left( \mathcal{T}_{2} \right)^{- 1} + \left( \mathcal{T}_{3} \right)^{- 1} + \left( \mathcal{T}_{4} \right)^{- 1} + \ldots + \left( \mathcal{T}_{\infty} \right)^{- 1} \right). \end{array}
(1.7.125)

After sub­sti­tut­ing our de­fined n\overline{n} and the T(s)\mathrm{T}(s) func­tion, the ex­pres­sion is equal to

ζ(1)=n−T(1),\begin{array}{r} \zeta(1) = \overline{n} - \mathrm{T}(1), \end{array}
(1.7.126)

and solv­ing for n\overline{n}, we find the fol­low­ing ad­di­tive in­verse equal­i­ty

n=ζ(1)+T(1),\begin{array}{r} \overline{n} = \zeta(1) + \mathrm{T}(1), \end{array}
(1.7.127)

which is con­sis­tent with the ad­di­tive in­verse prop­er­ties in the de­f­i­n­i­tion for T(s).\mathrm{T}(s).This equal­i­ty, along with the spe­cif­ic so­lu­tion to our pre­vi­ous proof

n=T(s)+∏p prime11−p−s,\begin{array}{r} \overline{n} = \mathrm{T}(s) + \prod_{p\ prime}^{}\frac{1}{1 - p^{- s}}, \end{array}
(1.7.128)

present the means to un­der­stand the in­fin­i­ty of ones math­e­mat­i­cal­ly. Specif­i­cal­ly, how it splits into the el­e­ments of the har­mon­ic series with the el­e­ment-by-el­e­ment ad­di­tive in­verse series of in­verse tri­an­gu­lar num­bers. We can also define a very con­cise equal­i­ty for the iden­ti­ty by solv­ing for 11 in the fol­low­ing ex­pres­sion from our proof

n=T(s)+∏p prime11−p−s\overline{n} = \mathrm{T}(s) + \prod_{p\ prime}^{}\frac{1}{1 - p^{- s}}
→n−T(s)=∏p prime11−p−s→(n−T(s))(∏p prime1−p−s)=1,\begin{array}{r} \rightarrow \overline{n} - \mathrm{T}(s) = \prod_{p\ prime}^{}\frac{1}{1 - p^{- s}} \rightarrow \left( \overline{n} - \mathrm{T}(s) \right)\left( \prod_{p\ prime}^{}{1 - p^{- s}} \right) = 1, \end{array}
(1.7.129)

where the dif­fer­ence be­tween prod­ucts of two dis­tinct in­fi­nite series with the in­fi­nite prod­uct of rec­i­p­ro­cal primes yields the iden­ti­ty. Given that

ζ(s)=n−T(s),\begin{array}{r} \zeta(s) = \overline{n} - \mathrm{T}(s), \end{array}
(1.7.130)

this is also equiv­a­lent to our iden­ti­ty ex­pres­sion

ζ(s)(∏p prime1−p−s)=1,\begin{array}{r} \zeta(s)\left( \prod_{p\ prime}^{}{1 - p^{- s}} \right) = 1, \end{array}
(1.7.131)

and once again, math­e­mat­ics never fails to im­press with its beauty and co­he­sive­ness.

We turn to prime num­bers and their rep­re­sen­ta­tions in group theory. This book has fo­cused on the prime number p2=3p_{2} = 3, from the stand­point of groups, and the geo­met­ric prime is en­cap­su­lat­ed in matrix al­ge­bra as the set A(gp2)A\left( gp_{2} \right), com­posed of the fol­low­ing two gen­er­a­tors

A(gp2)={(010001100),(001100010),(100010001)}.\begin{array}{r} A\left( gp_{2} \right) = \left\{ \begin{pmatrix} 0 & 1 & 0 \\ 0 & 0 & 1 \\ 1 & 0 & 0 \end{pmatrix},\begin{pmatrix} 0 & 0 & 1 \\ 1 & 0 & 0 \\ 0 & 1 & 0 \end{pmatrix},\begin{pmatrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{pmatrix} \right\}. \end{array}
(1.7.132)

The ma­tri­ces are the same Y2,Y3Y_{2},Y_{3} gen­er­a­tors from our group theory study but differ re­gard­ing their di­rec­tion of ro­ta­tion when acting on a po­si­tion vector. To show this math­e­mat­i­cal­ly, we define a vector v2=(e2iπ,e2iπ3,e4iπ3)Tv_{2} = \left( e^{2i\pi},e^{\frac{2i\pi}{3}},e^{\frac{4i\pi}{3}} \right)^{T}, which rep­re­sents the three ver­tices of the in­scribed geo­met­ric prime gp2gp_{2} arranged in coun­ter­clock­wise order from left to right, and take the fol­low­ing matrix-vector prod­uct

(010001100)(e2iπe2iπ3e4iπ3)=(e2iπ3e4iπ3e2iπ),\begin{array}{r} \begin{pmatrix} 0 & 1 & 0 \\ 0 & 0 & 1 \\ 1 & 0 & 0 \end{pmatrix}\begin{pmatrix} e^{2i\pi} \\ e^{\frac{2i\pi}{3}} \\ e^{\frac{4i\pi}{3}} \end{pmatrix} = \begin{pmatrix} e^{\frac{2i\pi}{3}} \\ e^{\frac{4i\pi}{3}} \\ e^{2i\pi} \end{pmatrix}, \end{array}
(1.7.133)

which rep­re­sents a clock­wise ro­ta­tion of the ver­tices by 2iπ3\frac{2i\pi}{3} ra­di­ans, shown in the figure below.

Figure
Figure 1.7.7 –Clock­wise ro­ta­tion­al trans­form of gp2gp_{2} ∈ℂ\in \mathbb{C}, by Y2×v2Y_{2} \times v_{2} matrix prod­uct. A red tri­an­gle rep­re­sents the ini­tial co­or­di­nates of ver­tices, and a blue tri­an­gle shows the final co­or­di­nates of ver­tices.

As stated, we find that the matrix-vector prod­uct Y3×v2Y_{3} \times v_{2}, ro­tates the plane in the op­po­site di­rec­tion, coun­ter­clock­wise, given that

(001100010)(e2iπe2iπ3e4iπ3)=(e4iπ3e2iπe2iπ3),\begin{array}{r} \begin{pmatrix} 0 & 0 & 1 \\ 1 & 0 & 0 \\ 0 & 1 & 0 \end{pmatrix}\begin{pmatrix} e^{2i\pi} \\ e^{\frac{2i\pi}{3}} \\ e^{\frac{4i\pi}{3}} \end{pmatrix} = \begin{pmatrix} e^{\frac{4i\pi}{3}} \\ e^{2i\pi} \\ e^{\frac{2i\pi}{3}} \end{pmatrix}, \end{array}
(1.7.134)

whose trans­form we show in the figure below.

Figure
Figure 1.7.8 –Coun­ter­clock­wise ro­ta­tion­al trans­form of gp2gp_{2} com­plex plane, by Y3×v2Y_{3} \times v_{2} matrix prod­uct, the red tri­an­gle rep­re­sents the ini­tial co­or­di­nate lo­ca­tions of ver­tices, blue tri­an­gle shows the final vertex co­or­di­nates.

We direct the reader's at­ten­tion to the 3×33 \times 3 matrix below

(ααααααααα),\begin{array}{r} \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix}, \end{array}
(1.7.135)

where α\alpha is just a dummy vari­able, and like the prime number 33, the matrix cannot be split equal­ly into small­er sub­ma­tri­ces, except for 1×11 \times 1 sizes and itself, 3×33 \times 3. We com­pare this to the com­pos­ite geom­e­try of the in­te­ger nine,ℤ9,\mathbb{Z}_{9}, which has a square matrix rep­re­sen­ta­tion, but we can divide the matrix into nine even 3×33 \times 3 sec­tions

(ααααααααααααααααααααααααααααααααααααααααααααααααααααααααααααααααααααααααααααααααα)→(ααααααααα)(ααααααααα)(ααααααααα)(ααααααααα)(ααααααααα)(ααααααααα)(ααααααααα)(ααααααααα)(ααααααααα),\begin{array}{r} \begin{pmatrix} \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \end{pmatrix} \rightarrow \begin{matrix} \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} \\ \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} \\ \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} \end{matrix}, \end{array}
(1.7.136)

which un­der­scores the fact it is com­posed of gp2gp_{2} ma­tri­ces, and this sec­tion­ing of the ℤ9\mathbb{Z}_{9} matrix is the only way to do so. Com­pare this to the com­pos­ite geom­e­try of the in­te­ger 6,ℤ66,\mathbb{Z}_{6}, which has two unique ways to evenly sec­tion its matrix

(αααααααααααααααααααααααααααααααααααα)→(ααααααααα)(ααααααααα)(ααααααααα)(ααααααααα),\begin{array}{r} \begin{pmatrix} \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \end{pmatrix} \rightarrow \begin{matrix} \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} \\ \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha \end{pmatrix} \end{matrix}, \end{array}
(1.7.137)
(αααααααααααααααααααααααααααααααααααα)→(αααα)(αααα)(αααα)(αααα)(αααα)(αααα)(αααα)(αααα)(αααα),\begin{array}{r} \begin{pmatrix} \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \\ \alpha & \alpha & \alpha & \alpha & \alpha & \alpha \end{pmatrix} \rightarrow \begin{matrix} \begin{pmatrix} \alpha & \alpha \\ \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha \\ \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha \\ \alpha & \alpha \end{pmatrix} \\ \begin{pmatrix} \alpha & \alpha \\ \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha \\ \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha \\ \alpha & \alpha \end{pmatrix} \\ \begin{pmatrix} \alpha & \alpha \\ \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha \\ \alpha & \alpha \end{pmatrix} & \begin{pmatrix} \alpha & \alpha \\ \alpha & \alpha \end{pmatrix} \end{matrix}, \end{array}
(1.7.138)

where the first rep­re­sents a 2×22 \times 2 sec­tion­ing of 3×33 \times 3 ma­tri­ces, and the second a 3×33 \times 3 sec­tion­ing of 2×22 \times 2 ma­tri­ces, sig­ni­fy­ing ℤ6\mathbb{Z}_{6} is com­posed of the geo­met­ric prime num­bers gp1gp_{1} and gp2gp_{2}.

For the geo­met­ric prime set A(gp2),A\left( gp_{2} \right),

A(gp2)={(010001100),(001100010),(100010001)},\begin{array}{r} A\left( gp_{2} \right) = \left\{ \begin{pmatrix} 0 & 1 & 0 \\ 0 & 0 & 1 \\ 1 & 0 & 0 \end{pmatrix},\begin{pmatrix} 0 & 0 & 1 \\ 1 & 0 & 0 \\ 0 & 1 & 0 \end{pmatrix},\begin{pmatrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{pmatrix} \right\}, \end{array}
(1.7.139)

we now return to the anti-di­ag­o­nal sym­me­try of the Cartan al­ge­bra dis­cus­sion in Sec­tion 1.2.9, where each Lie al­ge­bra gen­er­a­tor in the set A(gp2)A\left( gp_{2} \right) has sym­me­try about the anti-di­ag­o­nal axis. The iden­ti­ty matrix rep­re­sents the di­ag­o­nal axis, and, when taken as a prod­uct with an­oth­er matrix, acts to scale the values of that matrix's en­tries. The anti-iden­ti­ty matrix can be thought of as the analog of the re­la­tion­ship the iden­ti­ty matrix has with the di­ag­o­nal, and this anti-iden­ti­ty matrix we will define as

ϵ∗=Y1∗=(001010100),\begin{array}{r} \epsilon^{*} = Y_{1}^{*} = \begin{pmatrix} 0 & 0 & 1 \\ 0 & 1 & 0 \\ 1 & 0 & 0 \end{pmatrix}, \end{array}
(1.7.140)

which is the same as the X2X_{2}-type Lie al­ge­bra that we have de­fined pre­vi­ous­ly. Sim­i­lar­ly, we can define that

X1=Y2∗=(100001010),   X3=Y3∗=(010100001),\begin{array}{r} X_{1} = Y_{2}^{*} = \begin{pmatrix} 1 & 0 & 0 \\ 0 & 0 & 1 \\ 0 & 1 & 0 \end{pmatrix},\ \ \ {X_{3} = Y}_{3}^{*} = \begin{pmatrix} 0 & 1 & 0 \\ 1 & 0 & 0 \\ 0 & 0 & 1 \end{pmatrix}, \end{array}
(1.7.141)

which we arrive at by ro­tat­ing the Y2Y_{2} and Y3Y_{3} Lie al­ge­bras by 90 de­grees in the clock­wise di­rec­tion, and the reader should con­sid­er these trans­forms as higher-di­men­sion­al ro­ta­tions of the gp2gp_{2} geo­met­ric prime. From the stand­point of matrix rep­re­sen­ta­tion theory, these di­men­sion­al trans­forms are the result of the prod­uct of the ro­ta­tion matrix ϵ∗\epsilon^{*}, with the el­e­ments of the set A(gp2)A\left( gp_{2} \right), seen as fol­lows

ϵ∗×Y2=X1→(001010100)(010001100)=(100001010),\epsilon^{*} \times Y_{2} = X_{1} \rightarrow \begin{pmatrix} 0 & 0 & 1 \\ 0 & 1 & 0 \\ 1 & 0 & 0 \end{pmatrix}\begin{pmatrix} 0 & 1 & 0 \\ 0 & 0 & 1 \\ 1 & 0 & 0 \end{pmatrix} = \begin{pmatrix} 1 & 0 & 0 \\ 0 & 0 & 1 \\ 0 & 1 & 0 \end{pmatrix},
ϵ∗×Y3=X3→(001010100)(001100010)=(010100001),\epsilon^{*} \times Y_{3} = X_{3} \rightarrow \begin{pmatrix} 0 & 0 & 1 \\ 0 & 1 & 0 \\ 1 & 0 & 0 \end{pmatrix}\begin{pmatrix} 0 & 0 & 1 \\ 1 & 0 & 0 \\ 0 & 1 & 0 \end{pmatrix} = \begin{pmatrix} 0 & 1 & 0 \\ 1 & 0 & 0 \\ 0 & 0 & 1 \end{pmatrix},
ϵ∗×Y1=X2→(001010100)(100010001)=(001010100).\begin{array}{r} \epsilon^{*} \times Y_{1} = X_{2} \rightarrow \begin{pmatrix} 0 & 0 & 1 \\ 0 & 1 & 0 \\ 1 & 0 & 0 \end{pmatrix}\begin{pmatrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{pmatrix} = \begin{pmatrix} 0 & 0 & 1 \\ 0 & 1 & 0 \\ 1 & 0 & 0 \end{pmatrix}. \end{array}
(1.7.142)

It is im­por­tant to note that any of the XX-type ma­tri­ces can gen­er­ate the same matrix-matrix prod­ucts above, and our choice to use the anti-iden­ti­ty matrix, ϵ∗\epsilon^{*}, has its basis in main­tain­ing con­sis­ten­cy.

To better un­der­stand the higher-di­men­sion­al ro­ta­tions of the gp2gp_{2} geo­met­ric prime al­ge­bras, we show in the figure below the arrange­ment of the YY al­ge­bras along the edges of the equi­lat­er­al tri­an­gle, where each al­ge­bra is po­si­tioned on the edge co­in­cid­ing with its vertex sym­me­try (yellow arrows). Ad­di­tion­al­ly, the el­e­ments of the al­ge­bras are rep­re­sent­ed as red cir­cles, in­stead of 11 s, in each of the squares.

Figure
Figure 1.7.9 – The gp2gp_{2} geo­met­ric prime al­ge­bras arranged on the edges of each al­ge­bra's vertex sym­me­try.
Figure
Figure 1.7.10 – The gp2gp_{2} geo­met­ric prime set ro­ta­tion ϵ∗×A(gp2)={X1,X3,X2}\epsilon^{*} \times A\left( gp_{2} \right) = \left\{ X_{1},X_{3},X_{2} \right\}, squares con­tain­ing the red cir­cles rep­re­sent the gp2gp_{2} geo­met­ric prime al­ge­bras and the squares with green cir­cles rep­re­sent the set of al­ge­bras {X1,X3,X2}\left\{ X_{1},X_{3},X_{2} \right\}.

Next, we look at the set of Lie al­ge­bra gen­er­a­tor ro­ta­tions ϵ∗×A(gp2)={X1,X3,X2}\epsilon^{*} \times A\left( gp_{2} \right) = \left\{ X_{1},X_{3},X_{2} \right\} in matrix form as

(001010100){(010001100),(001100010),(100010001)}={(100001010),(010100001),(001010100)},\begin{array}{r} \begin{pmatrix} 0 & 0 & 1 \\ 0 & 1 & 0 \\ 1 & 0 & 0 \end{pmatrix}\left\{ \begin{pmatrix} 0 & 1 & 0 \\ 0 & 0 & 1 \\ 1 & 0 & 0 \end{pmatrix},\begin{pmatrix} 0 & 0 & 1 \\ 1 & 0 & 0 \\ 0 & 1 & 0 \end{pmatrix},\begin{pmatrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{pmatrix} \right\} = \left\{ \begin{pmatrix} 1 & 0 & 0 \\ 0 & 0 & 1 \\ 0 & 1 & 0 \end{pmatrix},\begin{pmatrix} 0 & 1 & 0 \\ 1 & 0 & 0 \\ 0 & 0 & 1 \end{pmatrix},\begin{pmatrix} 0 & 0 & 1 \\ 0 & 1 & 0 \\ 1 & 0 & 0 \end{pmatrix} \right\}, \end{array}
(1.7.143)

and con­sid­er the ex­ten­sion of the geo­met­ric prime, gp2,gp_{2},into the higher-di­men­sion­al ℂ3\mathbb{C}^{3} space, which is pre­sent­ed in Figure 1.7.10. We can see in the figure that each gp2gp_{2} al­ge­bra projects into the higher di­men­sion of its spe­cif­ic XX al­ge­bra, which is onto a face of the tri­an­gu­lar prism rising from the gp2gp_{2} geo­met­ric prime's equi­lat­er­al tri­an­gle.

Just as the prime num­bers are the build­ing blocks for the in­te­gers, the geo­met­ric primes are the sine qua non of the Lie al­ge­bras we have stud­ied. In the higher-di­men­sion­al com­plex spaces, the geo­met­ric primes are the build­ing blocks of the com­pos­ite nn-gons. Still, we will find they are re­spon­si­ble for build­ing the al­ge­bra's di­men­sions, and we will touch upon this sub­ject in the next sec­tion.

We return to the in­verse tri­an­gu­lar number set A((𝒯n)−1)A\left( \left( \mathcal{T}_{n} \right)^{- 1} \right)

A((𝒯n)−1)=2×{(1−12),(1−13),(1−14),(1−15),(1−16),(1−17),…},\begin{array}{r} A\left( \left( \mathcal{T}_{n} \right)^{- 1} \right) = 2 \times \left\{ \left( 1 - \frac{1}{2} \right),\left( 1 - \frac{1}{3} \right),\left( 1 - \frac{1}{4} \right),\left( 1 - \frac{1}{5} \right),\left( 1 - \frac{1}{6} \right),\left( 1 - \frac{1}{7} \right),\ldots \right\}, \end{array}
(1.7.144)

to fur­ther con­sid­er how it is re­lat­ed to the min­i­mal el­e­ment, 𝓂ℯ[1/n]\mathcal{m}\mathcal{e}_{\lbrack 1/n\rbrack}, which we recall is de­fined as

𝓂ℯ[1n]=(e2iπ)1n=(e2iπn).\begin{array}{r} \mathcal{m}\mathcal{e}_{\left\lbrack \frac{1}{n} \right\rbrack} = \left( e^{2i\pi} \right)^{\frac{1}{n}} = \left( e^{\frac{2i\pi}{n}} \right). \end{array}
(1.7.145)

When as­sum­ing a pos­i­tive-valued ℯ[+1/n]\mathcal{e}_{\lbrack + 1/n\rbrack}, the first vertex of the rep­re­sen­ta­tive nn-gon will be ori­ent­ed at a counter-clock­wise dis­tance of 2iπn\frac{2i\pi}{n} ra­di­ans from the iden­ti­ty. We take the A((𝒯n)−1)A\left( \left( \mathcal{T}_{n} \right)^{- 1} \right) set and con­sid­er its values to be on the com­plex unit circle and in ra­di­ans, where iπ(𝒯n)−1{i\pi\left( \mathcal{T}_{n} \right)}^{- 1} is equal to

iπ(𝒯n)−1=2iπnn+1,\begin{array}{r} {i\pi\left( \mathcal{T}_{n} \right)}^{- 1} = \frac{2i\pi n}{n + 1}, \end{array}
(1.7.146)

and the set A(iπ(𝒯n)−1)A\left( {i\pi\left( \mathcal{T}_{n} \right)}^{- 1} \right) would then equal

A(iπ(𝒯n)−1)=2iπ×{(1−12),(1−13),(1−14),(1−15),(1−16),(1−17),…}.\begin{array}{r} A\left( {i\pi\left( \mathcal{T}_{n} \right)}^{- 1} \right) = 2i\pi \times \left\{ \left( 1 - \frac{1}{2} \right),\left( 1 - \frac{1}{3} \right),\left( 1 - \frac{1}{4} \right),\left( 1 - \frac{1}{5} \right),\left( 1 - \frac{1}{6} \right),\left( 1 - \frac{1}{7} \right),\ldots \right\}. \end{array}
(1.7.147)

Each value in the A(iπ(𝒯n)−1)A\left( {i\pi\left( \mathcal{T}_{n} \right)}^{- 1} \right) rep­re­sents the first vertex of the rep­re­sen­ta­tive nn-gon from the iden­ti­ty in the clock­wise ori­en­ta­tion and rep­re­sents the ar­gu­ment that de­fines the neg­a­tive-valued min­i­mal el­e­ment, 𝓂ℯ[−1/n]\mathcal{m}\mathcal{e}_{\lbrack - 1/n\rbrack}. In the case of the gp2gp_{2} geo­met­ric prime, 𝓂ℯ[−1/3]\mathcal{m}\mathcal{e}_{\lbrack - 1/3\rbrack} is equal to

𝓂ℯ[−13]=(e2iπ)(− 13)=e(− 2iπ3),\begin{array}{r} \mathcal{m}\mathcal{e}_{\left\lbrack - \frac{1}{3} \right\rbrack} = \left( e^{2i\pi} \right)^{\left( - \ \frac{1}{3} \right)} = e^{\left( - \ \frac{2i\pi}{3} \right)}, \end{array}
(1.7.148)

which has the equiv­a­lent form with a pos­i­tive­ly valued ar­gu­ment

𝓂ℯ[−13]=e(− 2iπ3)=e(4iπ3).\begin{array}{r} \mathcal{m}\mathcal{e}_{\left\lbrack - \frac{1}{3} \right\rbrack} = e^{\left( - \ \frac{2i\pi}{3} \right)} = e^{\left( \frac{4i\pi}{3} \right)}. \end{array}
(1.7.149)

By con­sid­er­ing the in­verse tri­an­gu­lar sum iπ(𝒯3)−1=2iπ(1−13){i\pi\left( \mathcal{T}_{3} \right)}^{- 1} = 2i\pi\left( 1 - \frac{1}{3} \right), we find it equals the same ar­gu­ment above, given that

eiπ(𝒯3)−1=e2iπ(1− 13)=e(4iπ3),\begin{array}{r} e^{{i\pi\left( \mathcal{T}_{3} \right)}^{- 1}} = e^{2i\pi\left( 1 - \ \frac{1}{3} \right)} = e^{\left( \frac{4i\pi}{3} \right)}, \end{array}
(1.7.150)

and the same is true for all el­e­ments in the set A(iπ(𝒯n)−1),A\left( {i\pi\left( \mathcal{T}_{n} \right)}^{- 1} \right),where the neg­a­tive-valued min­i­mal el­e­ment, 𝓂ℯ−[1n]\mathcal{m}\mathcal{e}_{- \left\lbrack \frac{1}{n} \right\rbrack}, is equal to

𝓂ℯ−[1n]=eiπ(𝒯n)−1=e(2iπ(n−1)n).\begin{array}{r} \mathcal{m}\mathcal{e}_{- \left\lbrack \frac{1}{n} \right\rbrack} = e^{{i\pi\left( \mathcal{T}_{n} \right)}^{- 1}} = e^{\left( \frac{2i\pi(n - 1)}{n} \right)}. \end{array}
(1.7.151)

Going back to the Euler prod­uct we de­scribed,

∮ζ(1)z dz=∮1z dz(1(1−12)(1−13)(1−15)(1−17)(1−111)(1−113)…),\begin{array}{r} \oint_{}^{}{\frac{\zeta(1)}{z}\ dz} = \oint_{}^{}{\frac{1}{z}\ dz}\left( \frac{1}{\left( 1 - \frac{1}{2} \right)\left( 1 - \frac{1}{3} \right)\left( 1 - \frac{1}{5} \right)\left( 1 - \frac{1}{7} \right)\left( 1 - \frac{1}{11} \right)\left( 1 - \frac{1}{13} \right)\ldots} \right), \end{array}
(1.7.152)

where the con­tour in­te­gral ∮z−1 dz\oint_{}^{}{z^{- 1}\ dz}, we know is equal to 2iπ2i\pi, it be­comes clear that the terms con­tain­ing the rec­i­p­ro­cal primes (1−1pn)\left( 1 - \frac{1}{p_{n}} \right) are equal to the rec­i­p­ro­cal primes of the set A(iπ(𝒯n)−1)A\left( {i\pi\left( \mathcal{T}_{n} \right)}^{- 1} \right), which we define as A(iπ(𝒯pn)−1)A\left( {i\pi\left( \mathcal{T}_{p_{n}} \right)}^{- 1} \right)

A(iπ(𝒯pn)−1)=2iπ×{(1−12),(1−13),(1−15),(1−17),(1−111),…},\begin{array}{r} A\left( {i\pi\left( \mathcal{T}_{p_{n}} \right)}^{- 1} \right) = 2i\pi \times \left\{ \left( 1 - \frac{1}{2} \right),\left( 1 - \frac{1}{3} \right),\left( 1 - \frac{1}{5} \right),\left( 1 - \frac{1}{7} \right),\left( 1 - \frac{1}{11} \right),\ldots \right\}, \end{array}
(1.7.153)

and this set also rep­re­sents the radian dis­tance of the neg­a­tive min­i­mal el­e­ment 𝓂ℯ−[1n]\mathcal{m}\mathcal{e}_{- \left\lbrack \frac{1}{n} \right\rbrack}, for rec­i­p­ro­cal prime values, de­fined as A(𝓂ℯ[−1pn]),A\left( \mathcal{m}\mathcal{e}_{\left\lbrack - \frac{1}{p_{n}} \right\rbrack} \right),

A(𝓂ℯ[−1pn])={e2iπ(1−12),e2iπ(1−13),e2iπ(1−15),e2iπ(1−17),e2iπ(1−111),…}.\begin{array}{r} A\left( \mathcal{m}\mathcal{e}_{\left\lbrack - \frac{1}{p_{n}} \right\rbrack} \right) = \left\{ e^{2i\pi\left( 1 - \frac{1}{2} \right)},e^{2i\pi\left( 1 - \frac{1}{3} \right)},e^{2i\pi\left( 1 - \frac{1}{5} \right)},e^{2i\pi\left( 1 - \frac{1}{7} \right)},e^{2i\pi\left( 1 - \frac{1}{11} \right)},\ldots \right\}. \end{array}
(1.7.154)

Sim­i­lar­ly, the pos­i­tive-valued min­i­mal el­e­ments with rec­i­p­ro­cal prime values, are de­fined as

A(𝓂ℯ[+1pn])={e2iπ(12),e2iπ(13),e2iπ(15),e2iπ(17),e2iπ(111),…},\begin{array}{r} A\left( \mathcal{m}\mathcal{e}_{\left\lbrack + \frac{1}{p_{n}} \right\rbrack} \right) = \left\{ e^{2i\pi\left( \frac{1}{2} \right)},e^{2i\pi\left( \frac{1}{3} \right)},e^{2i\pi\left( \frac{1}{5} \right)},e^{2i\pi\left( \frac{1}{7} \right)},e^{2i\pi\left( \frac{1}{11} \right)},\ldots \right\}, \end{array}
(1.7.155)

and el­e­ments be­tween the sets with like rec­i­p­ro­cal prime number basis are re­lat­ed as con­ju­gate pairs, where their prod­ucts are equal to the iden­ti­ty

(𝓂ℯ[+1pn])(𝓂ℯ[−1pn])=e2iπ(1−1pn)e2iπ(1pn)=e2iπ=1.\begin{array}{r} \left( \mathcal{m}\mathcal{e}_{\left\lbrack + \frac{1}{p_{n}} \right\rbrack} \right)\left( \mathcal{m}\mathcal{e}_{\left\lbrack - \frac{1}{p_{n}} \right\rbrack} \right) = e^{2i\pi\left( 1 - \frac{1}{p_{n}} \right)}e^{2i\pi\left( \frac{1}{p_{n}} \right)} = e^{2i\pi} = 1. \end{array}
(1.7.156)

For any nn-gon in­scribed in the com­plex unit circle, the value nn is the sum of con­ju­gate prod­uct pairs, given that

∑k=1ne2iπ(1−kn)e2iπ(kn)=∑k=1ne2iπ(1)=∑k=1n1,\begin{array}{r} \sum_{k = 1}^{n}{e^{2i\pi\left( 1 - \frac{k}{n} \right)}e^{2i\pi\left( \frac{k}{n} \right)}} = \sum_{k = 1}^{n}e^{2i\pi(1)} = \sum_{k = 1}^{n}1, \end{array}
(1.7.157)

and the par­tial sum of 1s1\text{s} is simply equal to nn

n=∑k=1n1.\begin{array}{r} n = \sum_{k = 1}^{n}1. \end{array}
(1.7.158)

We now have a geo­met­ric in­ter­pre­ta­tion of the prime num­bers, rep­re­sent­ing a solid foun­da­tion we will build upon in the next book in the Arith­moí series. In this sec­tion, we have found sev­er­al con­nec­tions prime num­bers have with group theory, higher di­men­sion­al com­plex spaces, and the tri­an­gu­lar num­bers, made pos­si­ble by putting the min­i­mal el­e­ment into its proper per­spec­tive.