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Edit detail for Octonion Algebra is Frobenius in Just One Way revision 7 of 8

1 2 3 4 5 6 7 8
Editor: Bill Page
Time: 2011/05/06 10:17:07 GMT-7
Note: use new LOP

changed:
-)library CARTEN MONAL PROP LIN CALEY
-\end{axiom}
)library CARTEN MONAL PROP LOP CALEY
\end{axiom}

changed:
-𝐋 := LinearOperator(dim, OVAR [], ℚ)
-𝐞:ℒ 𝐋      := basisVectors()
-𝐝:ℒ 𝐋      := basisForms()
𝐋 := LinearOperator(OVAR ['0,'1,'2,'3,'4,'5,'6,'7], ℚ)
𝐞:ℒ 𝐋      := basisOut()
𝐝:ℒ 𝐋      := basisIn()

Octonion Algebra Is Frobenius In Just One Way

Linear operators over a 8-dimensional vector space representing octonnion algebra

Ref:

We need the Axiom LinearOperator? library.

fricas
(1) -> )library CARTEN MONAL PROP LOP CALEY
CartesianTensor is now explicitly exposed in frame initial CartesianTensor will be automatically loaded when needed from /var/aw/var/LatexWiki/CARTEN.NRLIB/CARTEN Monoidal is now explicitly exposed in frame initial Monoidal will be automatically loaded when needed from /var/aw/var/LatexWiki/MONAL.NRLIB/MONAL Prop is now explicitly exposed in frame initial Prop will be automatically loaded when needed from /var/aw/var/LatexWiki/PROP.NRLIB/PROP LinearOperator is now explicitly exposed in frame initial LinearOperator will be automatically loaded when needed from /var/aw/var/LatexWiki/LOP.NRLIB/LOP CaleyDickson is now explicitly exposed in frame initial CaleyDickson will be automatically loaded when needed from /var/aw/var/LatexWiki/CALEY.NRLIB/CALEY

Use the following macros for convenient notation

fricas
-- summation
macro Σ(x,i,n)==reduce(+,[x for i in n])
Type: Void
fricas
-- list
macro Ξ(f,i,n)==[f for i in n]
Type: Void
fricas
-- subscript
macro sb == subscript
Type: Void

𝐋 is the domain of 8-dimensional linear operators over the rational functions ℚ (Expression Integer), i.e. ratio of polynomials with integer coefficients.

fricas
dim:=8

\label{eq1}8(1)
Type: PositiveInteger?
fricas
macro ℒ == List
Type: Void
fricas
macro ℂ == CaleyDickson
Type: Void
fricas
macro ℚ == Expression Integer
Type: Void
fricas
𝐋 := LinearOperator(OVAR ['0,'1,'2,'3,'4,'5,'6,'7], ℚ)

\label{eq2}\hbox{\axiomType{LinearOperator}\ } \left({{\hbox{\axiomType{OrderedVariableList}\ } \left({\left[ 0, \: 1, \: 2, \: 3, \: 4, \: 5, \: 6, \: 7 \right]}\right)}, \:{\hbox{\axiomType{Expression}\ } \left({\hbox{\axiomType{Integer}\ }}\right)}}\right)(2)
Type: Type
fricas
𝐞:ℒ 𝐋      := basisOut()

\label{eq3}\left[{|_{0}}, \:{|_{1}}, \:{|_{2}}, \:{|_{3}}, \:{|_{4}}, \:{|_{5}}, \:{|_{6}}, \:{|_{7}}\right](3)
Type: List(LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer)))
fricas
𝐝:ℒ 𝐋      := basisIn()

\label{eq4}\left[{|_{\ }^{0}}, \:{|_{\ }^{1}}, \:{|_{\ }^{2}}, \:{|_{\ }^{3}}, \:{|_{\ }^{4}}, \:{|_{\ }^{5}}, \:{|_{\ }^{6}}, \:{|_{\ }^{7}}\right](4)
Type: List(LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer)))
fricas
I:𝐋:=[1];   -- identity for composition
Type: LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer))
fricas
X:𝐋:=[2,1]; -- twist
Type: LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer))

Now generate structure constants for Octonion Algebra

The basis consists of the real and imaginary units. We use quaternion multiplication to form the "multiplication table" as a matrix. Then the structure constants can be obtained by dividing each matrix entry by the list of basis vectors.

Split-complex, co-quaternions and split-octonions can be specified by Caley-Dickson parameters

fricas
--q0:=sb('q,[0])
q0:=1  -- not split-complex

\label{eq5}1(5)
Type: PositiveInteger?
fricas
--q1:=sb('q,[1])
q1:=1  -- not co-quaternion

\label{eq6}1(6)
Type: PositiveInteger?
fricas
q2:=sb('q,[2])

\label{eq7}q_{2}(7)
Type: Symbol
fricas
--q2:=1  -- split-octonion
QQ := ℂ(ℂ(ℂ(ℚ,'i,q0),'j,q1),'k,q2);
Type: Type

Basis: Each B.i is a octonion number

fricas
B:ℒ QQ := map(x +-> hyper x,1$SQMATRIX(dim,ℚ)::ℒ ℒ ℚ)

\label{eq8}\left[ 1, \: i , \: j , \:{ij}, \: k , \:{ik}, \:{jk}, \:{{ij}k}\right](8)
Type: List(CaleyDickson?(CaleyDickson?(CaleyDickson?(Expression(Integer),i,1),j,1),k,q[2]))
fricas
-- Multiplication table:
M:Matrix QQ := matrix Ξ(Ξ(B.i*B.j, i,1..dim), j,1..dim)

\label{eq9}\left[ 
\begin{array}{cccccccc}
1 & i & j &{ij}& k &{ik}&{jk}&{{ij}k}
\
i & - 1 & -{ij}& j &{- ik}& k &{{ij}k}& -{jk}
\
j &{ij}& - 1 & - i & -{jk}&{-{ij}k}& k &{ik}
\
{ij}& - j & i & - 1 &{-{ij}k}&{jk}&{- ik}& k 
\
k &{ik}&{jk}&{{ij}k}& -{q_{2}}&{-{q_{2}}i}&{-{q_{2}}j}&{{-{\overline{q_{2}}}i}j}
\
{ik}& - k &{{ij}k}& -{jk}&{{q_{2}}i}& -{q_{2}}&{{{q_{2}}i}j}&{-{\overline{q_{2}}}j}
\
{jk}&{-{ij}k}& - k &{ik}&{{q_{2}}j}&{{-{q_{2}}i}j}& -{q_{2}}&{{\overline{q_{2}}}i}
\
{{ij}k}&{jk}&{- ik}& - k &{{{\overline{q_{2}}}i}j}&{{\overline{q_{2}}}j}&{-{\overline{q_{2}}}i}& -{q_{2}}
(9)
Type: Matrix(CaleyDickson?(CaleyDickson?(CaleyDickson?(Expression(Integer),i,1),j,1),k,q[2]))
fricas
-- Function to divide the matrix entries by a basis element
S(y) == map(x +-> real real real(x/y),M)
Type: Void
fricas
-- The result is a nested list
ѕ :=map(S,B)::ℒ ℒ ℒ ℚ;
fricas
Compiling function S with type CaleyDickson(CaleyDickson(
      CaleyDickson(Expression(Integer),i,1),j,1),k,q[2]) -> Matrix(
      Expression(Integer))
Type: List(List(List(Expression(Integer))))
fricas
-- structure constants form a tensor operator
Y := Σ(Σ(Σ(ѕ(i)(k)(j)*𝐞.i*𝐝.j*𝐝.k, i,1..dim), j,1..dim), k,1..dim)

\label{eq10}\begin{array}{@{}l}
\displaystyle
{|_{0}^{0 \  0}}+{|_{1}^{0 \  1}}+{|_{2}^{0 \  2}}+{|_{3}^{0 \  3}}+{{\frac{q_{2}}{\overline{q_{2}}}}\ {|_{4}^{0 \  4}}}+{|_{5}^{0 \  5}}+ 
\
\
\displaystyle
{|_{6}^{0 \  6}}+{|_{7}^{0 \  7}}+{|_{1}^{1 \  0}}-{|_{0}^{1 \  1}}+{|_{3}^{1 \  2}}-{|_{2}^{1 \  3}}+{|_{5}^{1 \  4}}- 
\
\
\displaystyle
{{\frac{q_{2}}{\overline{q_{2}}}}\ {|_{4}^{1 \  5}}}-{|_{7}^{1 \  6}}+{|_{6}^{1 \  7}}+{|_{2}^{2 \  0}}-{|_{3}^{2 \  1}}-{|_{0}^{2 \  2}}+ 
\
\
\displaystyle
{|_{1}^{2 \  3}}+{|_{6}^{2 \  4}}+{|_{7}^{2 \  5}}-{{\frac{q_{2}}{\overline{q_{2}}}}\ {|_{4}^{2 \  6}}}-{|_{5}^{2 \  7}}+{|_{3}^{3 \  0}}+ 
\
\
\displaystyle
{|_{2}^{3 \  1}}-{|_{1}^{3 \  2}}-{|_{0}^{3 \  3}}+{|_{7}^{3 \  4}}-{|_{6}^{3 \  5}}+{|_{5}^{3 \  6}}- 
\
\
\displaystyle
{{\frac{q_{2}}{\overline{q_{2}}}}\ {|_{4}^{3 \  7}}}+{{\frac{q_{2}}{\overline{q_{2}}}}\ {|_{4}^{4 \  0}}}-{|_{5}^{4 \  1}}-{|_{6}^{4 \  2}}-{|_{7}^{4 \  3}}- 
\
\
\displaystyle
{{q_{2}}\ {|_{0}^{4 \  4}}}+{{q_{2}}\ {|_{1}^{4 \  5}}}+{{q_{2}}\ {|_{2}^{4 \  6}}}+{{q_{2}}\ {|_{3}^{4 \  7}}}+{|_{5}^{5 \  0}}+ \
\
\displaystyle
{{\frac{q_{2}}{\overline{q_{2}}}}\ {|_{4}^{5 \  1}}}-{|_{7}^{5 \  2}}+{|_{6}^{5 \  3}}-{{q_{2}}\ {|_{1}^{5 \  4}}}-{{q_{2}}\ {|_{0}^{5 \  5}}}- 
\
\
\displaystyle
{{\overline{q_{2}}}\ {|_{3}^{5 \  6}}}+{{\overline{q_{2}}}\ {|_{2}^{5 \  7}}}+{|_{6}^{6 \  0}}+{|_{7}^{6 \  1}}+{{\frac{q_{2}}{\overline{q_{2}}}}\ {|_{4}^{6 \  2}}}-{|_{5}^{6 \  3}}- 
\
\
\displaystyle
{{q_{2}}\ {|_{2}^{6 \  4}}}+{{\overline{q_{2}}}\ {|_{3}^{6 \  5}}}-{{q_{2}}\ {|_{0}^{6 \  6}}}-{{\overline{q_{2}}}\ {|_{1}^{6 \  7}}}+{|_{7}^{7 \  0}}-{|_{6}^{7 \  1}}+ 
\
\
\displaystyle
{|_{5}^{7 \  2}}+{{\frac{q_{2}}{\overline{q_{2}}}}\ {|_{4}^{7 \  3}}}-{{q_{2}}\ {|_{3}^{7 \  4}}}-{{\overline{q_{2}}}\ {|_{2}^{7 \  5}}}+{{\overline{q_{2}}}\ {|_{1}^{7 \  6}}}- 
\
\
\displaystyle
{{q_{2}}\ {|_{0}^{7 \  7}}}
(10)
Type: LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer))
fricas
arity Y

\label{eq11}\frac{2}{1}(11)
Type: Prop(LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer)))
fricas
matrix Ξ(Ξ((𝐞.i*𝐞.j)/Y, i,1..dim), j,1..dim)
>> System error: The value (0 . 0) is not of type UNSIGNED-BYTE

A scalar product is denoted by the (2,0)-tensor U = \{ u_{ij} \}

fricas
U:=Σ(Σ(script('u,[[],[i,j]])*𝐝.i*𝐝.j, i,1..dim), j,1..dim)

\label{eq12}\begin{array}{@{}l}
\displaystyle
{{u^{1, \: 1}}\ {|_{\ }^{0 \  0}}}+{{u^{1, \: 2}}\ {|_{\ }^{0 \  1}}}+{{u^{1, \: 3}}\ {|_{\ }^{0 \  2}}}+{{u^{1, \: 4}}\ {|_{\ }^{0 \  3}}}+ 
\
\
\displaystyle
{{u^{1, \: 5}}\ {|_{\ }^{0 \  4}}}+{{u^{1, \: 6}}\ {|_{\ }^{0 \  5}}}+{{u^{1, \: 7}}\ {|_{\ }^{0 \  6}}}+{{u^{1, \: 8}}\ {|_{\ }^{0 \  7}}}+ 
\
\
\displaystyle
{{u^{2, \: 1}}\ {|_{\ }^{1 \  0}}}+{{u^{2, \: 2}}\ {|_{\ }^{1 \  1}}}+{{u^{2, \: 3}}\ {|_{\ }^{1 \  2}}}+{{u^{2, \: 4}}\ {|_{\ }^{1 \  3}}}+ 
\
\
\displaystyle
{{u^{2, \: 5}}\ {|_{\ }^{1 \  4}}}+{{u^{2, \: 6}}\ {|_{\ }^{1 \  5}}}+{{u^{2, \: 7}}\ {|_{\ }^{1 \  6}}}+{{u^{2, \: 8}}\ {|_{\ }^{1 \  7}}}+ 
\
\
\displaystyle
{{u^{3, \: 1}}\ {|_{\ }^{2 \  0}}}+{{u^{3, \: 2}}\ {|_{\ }^{2 \  1}}}+{{u^{3, \: 3}}\ {|_{\ }^{2 \  2}}}+{{u^{3, \: 4}}\ {|_{\ }^{2 \  3}}}+ 
\
\
\displaystyle
{{u^{3, \: 5}}\ {|_{\ }^{2 \  4}}}+{{u^{3, \: 6}}\ {|_{\ }^{2 \  5}}}+{{u^{3, \: 7}}\ {|_{\ }^{2 \  6}}}+{{u^{3, \: 8}}\ {|_{\ }^{2 \  7}}}+ 
\
\
\displaystyle
{{u^{4, \: 1}}\ {|_{\ }^{3 \  0}}}+{{u^{4, \: 2}}\ {|_{\ }^{3 \  1}}}+{{u^{4, \: 3}}\ {|_{\ }^{3 \  2}}}+{{u^{4, \: 4}}\ {|_{\ }^{3 \  3}}}+ 
\
\
\displaystyle
{{u^{4, \: 5}}\ {|_{\ }^{3 \  4}}}+{{u^{4, \: 6}}\ {|_{\ }^{3 \  5}}}+{{u^{4, \: 7}}\ {|_{\ }^{3 \  6}}}+{{u^{4, \: 8}}\ {|_{\ }^{3 \  7}}}+ 
\
\
\displaystyle
{{u^{5, \: 1}}\ {|_{\ }^{4 \  0}}}+{{u^{5, \: 2}}\ {|_{\ }^{4 \  1}}}+{{u^{5, \: 3}}\ {|_{\ }^{4 \  2}}}+{{u^{5, \: 4}}\ {|_{\ }^{4 \  3}}}+ 
\
\
\displaystyle
{{u^{5, \: 5}}\ {|_{\ }^{4 \  4}}}+{{u^{5, \: 6}}\ {|_{\ }^{4 \  5}}}+{{u^{5, \: 7}}\ {|_{\ }^{4 \  6}}}+{{u^{5, \: 8}}\ {|_{\ }^{4 \  7}}}+ 
\
\
\displaystyle
{{u^{6, \: 1}}\ {|_{\ }^{5 \  0}}}+{{u^{6, \: 2}}\ {|_{\ }^{5 \  1}}}+{{u^{6, \: 3}}\ {|_{\ }^{5 \  2}}}+{{u^{6, \: 4}}\ {|_{\ }^{5 \  3}}}+ 
\
\
\displaystyle
{{u^{6, \: 5}}\ {|_{\ }^{5 \  4}}}+{{u^{6, \: 6}}\ {|_{\ }^{5 \  5}}}+{{u^{6, \: 7}}\ {|_{\ }^{5 \  6}}}+{{u^{6, \: 8}}\ {|_{\ }^{5 \  7}}}+ 
\
\
\displaystyle
{{u^{7, \: 1}}\ {|_{\ }^{6 \  0}}}+{{u^{7, \: 2}}\ {|_{\ }^{6 \  1}}}+{{u^{7, \: 3}}\ {|_{\ }^{6 \  2}}}+{{u^{7, \: 4}}\ {|_{\ }^{6 \  3}}}+ 
\
\
\displaystyle
{{u^{7, \: 5}}\ {|_{\ }^{6 \  4}}}+{{u^{7, \: 6}}\ {|_{\ }^{6 \  5}}}+{{u^{7, \: 7}}\ {|_{\ }^{6 \  6}}}+{{u^{7, \: 8}}\ {|_{\ }^{6 \  7}}}+ 
\
\
\displaystyle
{{u^{8, \: 1}}\ {|_{\ }^{7 \  0}}}+{{u^{8, \: 2}}\ {|_{\ }^{7 \  1}}}+{{u^{8, \: 3}}\ {|_{\ }^{7 \  2}}}+{{u^{8, \: 4}}\ {|_{\ }^{7 \  3}}}+ 
\
\
\displaystyle
{{u^{8, \: 5}}\ {|_{\ }^{7 \  4}}}+{{u^{8, \: 6}}\ {|_{\ }^{7 \  5}}}+{{u^{8, \: 7}}\ {|_{\ }^{7 \  6}}}+{{u^{8, \: 8}}\ {|_{\ }^{7 \  7}}}
(12)
Type: LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer))

Definition 1

We say that the scalar product is associative if the tensor equation holds:

    Y   =   Y
     U     U

In other words, if the (3,0)-tensor:


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\label{eq13}
  \Phi = \{ \phi^{ijk} = {y^e}_{ij} u_{ek} - u_{ie} {y_e}^{jk} \}
  (13)
(three-point function) is zero.

Using the LinearOperator? domain in Axiom and some carefully chosen symbols we can easily enter expressions that are both readable and interpreted by Axiom as "graphical calculus" diagrams describing complex products and compositions of linear operators.

fricas
ω:𝐋 :=(Y*I)/U  - (I*Y)/U;
>> System error: The value (0 . 0) is not of type UNSIGNED-BYTE

Definition 2

An algebra with a non-degenerate associative scalar product is called a [Frobenius Algebra]?.

We may consider the problem where multiplication Y is given, and look for all associative scalar products U = U(Y)

This problem can be solved using linear algebra.

fricas
)expose MCALCFN
MultiVariableCalculusFunctions is now explicitly exposed in frame initial J := jacobian(ravel ω,concat map(variables,ravel U)::ℒ Symbol);
Type: Matrix(Expression(Integer))
fricas
u := transpose matrix [concat map(variables,ravel U)::ℒ Symbol];
Type: Matrix(Polynomial(Integer))
fricas
J::OutputForm * u::OutputForm = 0

\label{eq14}\begin{array}{@{}l}
\displaystyle
{{\left[ 
\begin{array}{cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc}
0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 
(14)
Type: Equation(OutputForm?)
fricas
nrows(J),ncols(J)

\label{eq15}\left[ 1, \:{64}\right](15)
Type: Tuple(PositiveInteger?)

The matrix J transforms the coefficients of the tensor U into coefficients of the tensor \Phi. We are looking for the general linear family of tensors U=U(Y,p_i) such that J transforms U into \Phi=0 for any such U.

If the null space of the J matrix is not empty we can use the basis to find all non-trivial solutions for U:

fricas
Ñ:=nullSpace(J);
Type: List(Vector(Expression(Integer)))
fricas
ℰ:=map((x,y)+->x=y, concat
       map(variables,ravel U), entries Σ(sb('p,[i])*Ñ.i, i,1..#Ñ) )

\label{eq16}\begin{array}{@{}l}
\displaystyle
\left[{{u^{1, \: 1}}={p_{64}}}, \:{{u^{1, \: 2}}={p_{63}}}, \:{{u^{1, \: 3}}={p_{62}}}, \:{{u^{1, \: 4}}={p_{61}}}, \: \right.
\
\
\displaystyle
\left.{{u^{1, \: 5}}={p_{60}}}, \:{{u^{1, \: 6}}={p_{59}}}, \:{{u^{1, \: 7}}={p_{58}}}, \:{{u^{1, \: 8}}={p_{57}}}, \: \right.
\
\
\displaystyle
\left.{{u^{2, \: 1}}={p_{56}}}, \:{{u^{2, \: 2}}={p_{55}}}, \:{{u^{2, \: 3}}={p_{54}}}, \:{{u^{2, \: 4}}={p_{53}}}, \: \right.
\
\
\displaystyle
\left.{{u^{2, \: 5}}={p_{52}}}, \:{{u^{2, \: 6}}={p_{51}}}, \:{{u^{2, \: 7}}={p_{50}}}, \:{{u^{2, \: 8}}={p_{49}}}, \: \right.
\
\
\displaystyle
\left.{{u^{3, \: 1}}={p_{48}}}, \:{{u^{3, \: 2}}={p_{47}}}, \:{{u^{3, \: 3}}={p_{46}}}, \:{{u^{3, \: 4}}={p_{45}}}, \: \right.
\
\
\displaystyle
\left.{{u^{3, \: 5}}={p_{44}}}, \:{{u^{3, \: 6}}={p_{43}}}, \:{{u^{3, \: 7}}={p_{42}}}, \:{{u^{3, \: 8}}={p_{41}}}, \: \right.
\
\
\displaystyle
\left.{{u^{4, \: 1}}={p_{40}}}, \:{{u^{4, \: 2}}={p_{39}}}, \:{{u^{4, \: 3}}={p_{38}}}, \:{{u^{4, \: 4}}={p_{37}}}, \: \right.
\
\
\displaystyle
\left.{{u^{4, \: 5}}={p_{36}}}, \:{{u^{4, \: 6}}={p_{35}}}, \:{{u^{4, \: 7}}={p_{34}}}, \:{{u^{4, \: 8}}={p_{33}}}, \: \right.
\
\
\displaystyle
\left.{{u^{5, \: 1}}={p_{32}}}, \:{{u^{5, \: 2}}={p_{31}}}, \:{{u^{5, \: 3}}={p_{30}}}, \:{{u^{5, \: 4}}={p_{29}}}, \: \right.
\
\
\displaystyle
\left.{{u^{5, \: 5}}={p_{28}}}, \:{{u^{5, \: 6}}={p_{27}}}, \:{{u^{5, \: 7}}={p_{26}}}, \:{{u^{5, \: 8}}={p_{25}}}, \: \right.
\
\
\displaystyle
\left.{{u^{6, \: 1}}={p_{24}}}, \:{{u^{6, \: 2}}={p_{23}}}, \:{{u^{6, \: 3}}={p_{22}}}, \:{{u^{6, \: 4}}={p_{21}}}, \: \right.
\
\
\displaystyle
\left.{{u^{6, \: 5}}={p_{20}}}, \:{{u^{6, \: 6}}={p_{19}}}, \:{{u^{6, \: 7}}={p_{18}}}, \:{{u^{6, \: 8}}={p_{17}}}, \: \right.
\
\
\displaystyle
\left.{{u^{7, \: 1}}={p_{16}}}, \:{{u^{7, \: 2}}={p_{15}}}, \:{{u^{7, \: 3}}={p_{14}}}, \:{{u^{7, \: 4}}={p_{13}}}, \: \right.
\
\
\displaystyle
\left.{{u^{7, \: 5}}={p_{12}}}, \:{{u^{7, \: 6}}={p_{11}}}, \:{{u^{7, \: 7}}={p_{10}}}, \:{{u^{7, \: 8}}={p_{9}}}, \:{{u^{8, \: 1}}={p_{8}}}, \: \right.
\
\
\displaystyle
\left.{{u^{8, \: 2}}={p_{7}}}, \:{{u^{8, \: 3}}={p_{6}}}, \:{{u^{8, \: 4}}={p_{5}}}, \:{{u^{8, \: 5}}={p_{4}}}, \:{{u^{8, \: 6}}={p_{3}}}, \: \right.
\
\
\displaystyle
\left.{{u^{8, \: 7}}={p_{2}}}, \:{{u^{8, \: 8}}={p_{1}}}\right] (16)
Type: List(Equation(Expression(Integer)))

This defines a family of Frobenius algebras:

fricas
zero? eval(ω,ℰ)

\label{eq17} \mbox{\rm false} (17)
Type: Boolean

The pairing is necessarily diagonal!

fricas
Ų:𝐋 := eval(U,ℰ)

\label{eq18}\begin{array}{@{}l}
\displaystyle
{{p_{64}}\ {|_{\ }^{0 \  0}}}+{{p_{63}}\ {|_{\ }^{0 \  1}}}+{{p_{62}}\ {|_{\ }^{0 \  2}}}+{{p_{61}}\ {|_{\ }^{0 \  3}}}+{{p_{6
0}}\ {|_{\ }^{0 \  4}}}+ 
\
\
\displaystyle
{{p_{59}}\ {|_{\ }^{0 \  5}}}+{{p_{58}}\ {|_{\ }^{0 \  6}}}+{{p_{57}}\ {|_{\ }^{0 \  7}}}+{{p_{56}}\ {|_{\ }^{1 \  0}}}+{{p_{5
5}}\ {|_{\ }^{1 \  1}}}+ 
\
\
\displaystyle
{{p_{54}}\ {|_{\ }^{1 \  2}}}+{{p_{53}}\ {|_{\ }^{1 \  3}}}+{{p_{52}}\ {|_{\ }^{1 \  4}}}+{{p_{51}}\ {|_{\ }^{1 \  5}}}+{{p_{5
0}}\ {|_{\ }^{1 \  6}}}+ 
\
\
\displaystyle
{{p_{49}}\ {|_{\ }^{1 \  7}}}+{{p_{48}}\ {|_{\ }^{2 \  0}}}+{{p_{47}}\ {|_{\ }^{2 \  1}}}+{{p_{46}}\ {|_{\ }^{2 \  2}}}+{{p_{4
5}}\ {|_{\ }^{2 \  3}}}+ 
\
\
\displaystyle
{{p_{44}}\ {|_{\ }^{2 \  4}}}+{{p_{43}}\ {|_{\ }^{2 \  5}}}+{{p_{42}}\ {|_{\ }^{2 \  6}}}+{{p_{41}}\ {|_{\ }^{2 \  7}}}+{{p_{4
0}}\ {|_{\ }^{3 \  0}}}+ 
\
\
\displaystyle
{{p_{39}}\ {|_{\ }^{3 \  1}}}+{{p_{38}}\ {|_{\ }^{3 \  2}}}+{{p_{37}}\ {|_{\ }^{3 \  3}}}+{{p_{36}}\ {|_{\ }^{3 \  4}}}+{{p_{3
5}}\ {|_{\ }^{3 \  5}}}+ 
\
\
\displaystyle
{{p_{34}}\ {|_{\ }^{3 \  6}}}+{{p_{33}}\ {|_{\ }^{3 \  7}}}+{{p_{32}}\ {|_{\ }^{4 \  0}}}+{{p_{31}}\ {|_{\ }^{4 \  1}}}+{{p_{3
0}}\ {|_{\ }^{4 \  2}}}+ 
\
\
\displaystyle
{{p_{29}}\ {|_{\ }^{4 \  3}}}+{{p_{28}}\ {|_{\ }^{4 \  4}}}+{{p_{27}}\ {|_{\ }^{4 \  5}}}+{{p_{26}}\ {|_{\ }^{4 \  6}}}+{{p_{2
5}}\ {|_{\ }^{4 \  7}}}+ 
\
\
\displaystyle
{{p_{24}}\ {|_{\ }^{5 \  0}}}+{{p_{23}}\ {|_{\ }^{5 \  1}}}+{{p_{22}}\ {|_{\ }^{5 \  2}}}+{{p_{21}}\ {|_{\ }^{5 \  3}}}+{{p_{2
0}}\ {|_{\ }^{5 \  4}}}+ 
\
\
\displaystyle
{{p_{19}}\ {|_{\ }^{5 \  5}}}+{{p_{18}}\ {|_{\ }^{5 \  6}}}+{{p_{17}}\ {|_{\ }^{5 \  7}}}+{{p_{16}}\ {|_{\ }^{6 \  0}}}+{{p_{1
5}}\ {|_{\ }^{6 \  1}}}+ 
\
\
\displaystyle
{{p_{14}}\ {|_{\ }^{6 \  2}}}+{{p_{13}}\ {|_{\ }^{6 \  3}}}+{{p_{12}}\ {|_{\ }^{6 \  4}}}+{{p_{11}}\ {|_{\ }^{6 \  5}}}+{{p_{1
0}}\ {|_{\ }^{6 \  6}}}+ 
\
\
\displaystyle
{{p_{9}}\ {|_{\ }^{6 \  7}}}+{{p_{8}}\ {|_{\ }^{7 \  0}}}+{{p_{7}}\ {|_{\ }^{7 \  1}}}+{{p_{6}}\ {|_{\ }^{7 \  2}}}+{{p_{5}}\ {|_{\ }^{7 \  3}}}+{{p_{4}}\ {|_{\ }^{7 \  4}}}+ 
\
\
\displaystyle
{{p_{3}}\ {|_{\ }^{7 \  5}}}+{{p_{2}}\ {|_{\ }^{7 \  6}}}+{{p_{1}}\ {|_{\ }^{7 \  7}}}
(18)
Type: LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer))
fricas
matrix Ξ(Ξ((𝐞.i 𝐞.j)/Ų, i,1..dim), j,1..dim)
>> System error: The value (0 . 0) is not of type UNSIGNED-BYTE

The scalar product must be non-degenerate:

fricas
Ů:=determinant Ξ(Ξ(retract((𝐞.i * 𝐞.j)/Ų), j,1..dim), i,1..dim)
>> System error: The value (0 . 0) is not of type UNSIGNED-BYTE

Definition 3

Co-pairing

Solve the [Snake Relation]? as a system of linear equations.

fricas
Um:=matrix Ξ(Ξ((𝐞.i*𝐞.j)/Ų, i,1..dim), j,1..dim)
>> System error: The value (0 . 0) is not of type UNSIGNED-BYTE

Check "dimension" and the snake relations.

fricas
d:𝐋:=
       Ω    /
       X    /
       Ų
>> System error: The value (1 . "failed") is not of type UNSIGNED-BYTE

Definition 4

Co-algebra

Compute the "three-point" function and use it to define co-multiplication.

fricas
W:=(Y,I)/Ų
>> System error: The value (0 . 0) is not of type UNSIGNED-BYTE

fricas
test
     (    I Ω     )  /
     (     Y I    )  =  λ
>> System error: The value (1 . "failed") is not of type UNSIGNED-BYTE

Frobenius Condition

Octonion algebra fails the Frobenius Condition!

fricas
Χ :=
       Y    /
       λ
>> System error: The value (0 . 1) is not of type UNSIGNED-BYTE

Perhaps this is not too surprising since Octonion algebra is non-associative. Nevertheless Octonions are "Frobenius" in a more general sense because there is a non-degenerate associative pairing.

i = Unit of the algebra

fricas
i:=𝐞.1

\label{eq19}|_{0}(19)
Type: LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer))
fricas
test
         i     /
         λ     =    Ω
>> System error: The value (0 . 1) is not of type UNSIGNED-BYTE

Handle

fricas
H:𝐋 :=
         λ     /
         X     /
         Y
>> System error: The value (1 . "failed") is not of type UNSIGNED-BYTE

Definition 5

Co-unit
  i 
  U
  

fricas
ι:𝐋:=
    (    i I    ) /
    (     Ų     )
>> System error: The value (0 . 0) is not of type UNSIGNED-BYTE

Y=U
ι  
fricas
test
        Y    /
        ι       = Ų
>> System error: The value (0 . 1) is not of type UNSIGNED-BYTE

For example:

fricas
ex1:=[q[2]=1,p[1]=1]

\label{eq20}\left[{{q_{2}}= 1}, \:{{p_{1}}= 1}\right](20)
Type: List(Equation(Polynomial(Integer)))
fricas
Ų0:𝐋  :=eval(Ų,ex1)

\label{eq21}\begin{array}{@{}l}
\displaystyle
{{p_{64}}\ {|_{\ }^{0 \  0}}}+{{p_{63}}\ {|_{\ }^{0 \  1}}}+{{p_{62}}\ {|_{\ }^{0 \  2}}}+{{p_{61}}\ {|_{\ }^{0 \  3}}}+{{p_{6
0}}\ {|_{\ }^{0 \  4}}}+ 
\
\
\displaystyle
{{p_{59}}\ {|_{\ }^{0 \  5}}}+{{p_{58}}\ {|_{\ }^{0 \  6}}}+{{p_{57}}\ {|_{\ }^{0 \  7}}}+{{p_{56}}\ {|_{\ }^{1 \  0}}}+{{p_{5
5}}\ {|_{\ }^{1 \  1}}}+ 
\
\
\displaystyle
{{p_{54}}\ {|_{\ }^{1 \  2}}}+{{p_{53}}\ {|_{\ }^{1 \  3}}}+{{p_{52}}\ {|_{\ }^{1 \  4}}}+{{p_{51}}\ {|_{\ }^{1 \  5}}}+{{p_{5
0}}\ {|_{\ }^{1 \  6}}}+ 
\
\
\displaystyle
{{p_{49}}\ {|_{\ }^{1 \  7}}}+{{p_{48}}\ {|_{\ }^{2 \  0}}}+{{p_{47}}\ {|_{\ }^{2 \  1}}}+{{p_{46}}\ {|_{\ }^{2 \  2}}}+{{p_{4
5}}\ {|_{\ }^{2 \  3}}}+ 
\
\
\displaystyle
{{p_{44}}\ {|_{\ }^{2 \  4}}}+{{p_{43}}\ {|_{\ }^{2 \  5}}}+{{p_{42}}\ {|_{\ }^{2 \  6}}}+{{p_{41}}\ {|_{\ }^{2 \  7}}}+{{p_{4
0}}\ {|_{\ }^{3 \  0}}}+ 
\
\
\displaystyle
{{p_{39}}\ {|_{\ }^{3 \  1}}}+{{p_{38}}\ {|_{\ }^{3 \  2}}}+{{p_{37}}\ {|_{\ }^{3 \  3}}}+{{p_{36}}\ {|_{\ }^{3 \  4}}}+{{p_{3
5}}\ {|_{\ }^{3 \  5}}}+ 
\
\
\displaystyle
{{p_{34}}\ {|_{\ }^{3 \  6}}}+{{p_{33}}\ {|_{\ }^{3 \  7}}}+{{p_{32}}\ {|_{\ }^{4 \  0}}}+{{p_{31}}\ {|_{\ }^{4 \  1}}}+{{p_{3
0}}\ {|_{\ }^{4 \  2}}}+ 
\
\
\displaystyle
{{p_{29}}\ {|_{\ }^{4 \  3}}}+{{p_{28}}\ {|_{\ }^{4 \  4}}}+{{p_{27}}\ {|_{\ }^{4 \  5}}}+{{p_{26}}\ {|_{\ }^{4 \  6}}}+{{p_{2
5}}\ {|_{\ }^{4 \  7}}}+ 
\
\
\displaystyle
{{p_{24}}\ {|_{\ }^{5 \  0}}}+{{p_{23}}\ {|_{\ }^{5 \  1}}}+{{p_{22}}\ {|_{\ }^{5 \  2}}}+{{p_{21}}\ {|_{\ }^{5 \  3}}}+{{p_{2
0}}\ {|_{\ }^{5 \  4}}}+ 
\
\
\displaystyle
{{p_{19}}\ {|_{\ }^{5 \  5}}}+{{p_{18}}\ {|_{\ }^{5 \  6}}}+{{p_{17}}\ {|_{\ }^{5 \  7}}}+{{p_{16}}\ {|_{\ }^{6 \  0}}}+{{p_{1
5}}\ {|_{\ }^{6 \  1}}}+ 
\
\
\displaystyle
{{p_{14}}\ {|_{\ }^{6 \  2}}}+{{p_{13}}\ {|_{\ }^{6 \  3}}}+{{p_{12}}\ {|_{\ }^{6 \  4}}}+{{p_{11}}\ {|_{\ }^{6 \  5}}}+{{p_{1
0}}\ {|_{\ }^{6 \  6}}}+ 
\
\
\displaystyle
{{p_{9}}\ {|_{\ }^{6 \  7}}}+{{p_{8}}\ {|_{\ }^{7 \  0}}}+{{p_{7}}\ {|_{\ }^{7 \  1}}}+{{p_{6}}\ {|_{\ }^{7 \  2}}}+{{p_{5}}\ {|_{\ }^{7 \  3}}}+{{p_{4}}\ {|_{\ }^{7 \  4}}}+ 
\
\
\displaystyle
{{p_{3}}\ {|_{\ }^{7 \  5}}}+{{p_{2}}\ {|_{\ }^{7 \  6}}}+{|_{\ }^{7 \  7}}
(21)
Type: LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer))
fricas
Ω0:𝐋  :=eval(Ω,ex1)$𝐋

\label{eq22}��(22)
Type: LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer))
fricas
λ0:𝐋  :=eval(λ,ex1)$𝐋

\label{eq23}��(23)
Type: LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer))
fricas
H0:𝐋 :=eval(H,ex1)$𝐋

\label{eq24}H(24)
Type: LinearOperator?(OrderedVariableList?([0,1,2,3,4,5,6,7]),Expression(Integer))