The Pauli Algebra Cl(3) Is Frobenius In Many Ways
Linear operators over a 8-dimensional vector space representing Pauli algebra
Ref:
We need the Axiom LinearOperator? library.
axiom
)library CARTEN ARITY CMONAL CPROP CLOP CALEY
CartesianTensor is now explicitly exposed in frame initial
CartesianTensor will be automatically loaded when needed from
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Arity is now explicitly exposed in frame initial
Arity will be automatically loaded when needed from
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ClosedMonoidal is now explicitly exposed in frame initial
ClosedMonoidal will be automatically loaded when needed from
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ClosedProp is now explicitly exposed in frame initial
ClosedProp will be automatically loaded when needed from
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ClosedLinearOperator is now explicitly exposed in frame initial
ClosedLinearOperator will be automatically loaded when needed from
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CaleyDickson is now explicitly exposed in frame initial
CaleyDickson will be automatically loaded when needed from
/var/zope2/var/LatexWiki/CALEY.NRLIB/CALEY
Use the following macros for convenient notation
axiom
-- summation
macro Σ(x,i,n)==reduce(+,[x for i in n])
Type: Void
axiom
-- list
macro Ξ(f,i,n)==[f for i in n]
Type: Void
axiom
-- subscript and superscripts
macro sb == subscript
Type: Void
axiom
macro sp == superscript
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.
axiom
dim:=8
axiom
macro ℒ == List
Type: Void
axiom
macro ℂ == CaleyDickson
Type: Void
axiom
macro ℚ == Expression Integer
Type: Void
axiom
𝐋 := ClosedLinearOperator(OVAR ['1,'i,'j,'k,'ij,'ik,'jk,'ijk], ℚ)
Type: Type
axiom
𝐞:ℒ 𝐋 := basisOut()
Type: List(ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer)))
axiom
𝐝:ℒ 𝐋 := basisIn()
Type: List(ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer)))
axiom
I:𝐋:=[1] -- identity for composition
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
X:𝐋:=[2,1] -- twist
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
V:𝐋:=ev(1) -- evaluation
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
Λ:𝐋:=co(1) -- co-evaluation
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
equate(eq)==map((x,y)+->(x=y),ravel lhs eq, ravel rhs eq);
Type: Void
Now generate structure constants for Quaternion 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.
The Pauli Algebra as Cl(3)
Basis: Each B.i is a Clifford number
axiom
q0:=sp('i,[2])
Type: Symbol
axiom
q1:=sp('j,[2])
Type: Symbol
axiom
q2:=sp('k,[2])
Type: Symbol
axiom
QQ:=CliffordAlgebra(3,ℚ,matrix [[q0,0,0],[0,q1,0],[0,0,q2]])
Type: Type
axiom
B:ℒ QQ := [monomial(1,[]),monomial(1,[1]),monomial(1,[2]),monomial(1,[3]),monomial(1,[1,2]),monomial(1,[1,3]),monomial(1,[2,3]),monomial(1,[1,2,3])]
Type: List(CliffordAlgebra
?(3,
Expression(Integer),
[[*001i(2),
0,
0],
[0,
*001j(2),
0],
[0,
0,
*001k(2)]]))
axiom
M:Matrix QQ := matrix Ξ(Ξ(B.i*B.j, i,1..dim), j,1..dim)
Type: Matrix(CliffordAlgebra
?(3,
Expression(Integer),
[[*001i(2),
0,
0],
[0,
*001j(2),
0],
[0,
0,
*001k(2)]]))
axiom
S(y) == map(x +-> coefficient(recip(y)*x,[]),M)
Type: Void
axiom
ѕ :=map(S,B)::ℒ ℒ ℒ ℚ
axiom
Compiling function S with type CliffordAlgebra(3,Expression(Integer)
,[[*001i(2),0,0],[0,*001j(2),0],[0,0,*001k(2)]]) -> Matrix(
Expression(Integer))
Type: List(List(List(Expression(Integer))))
axiom
-- 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)
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
matrix Ξ(Ξ((𝐞.i*𝐞.j)/Y, i,1..dim), j,1..dim)
Type: Matrix(ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer)))
axiom
XY := X/Y;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
Multiplication is Associative
axiom
test(
( I Y ) / _
( Y ) = _
( Y I ) / _
( Y ) )
Type: Boolean
A scalar product is denoted by the (2,0)-tensor
axiom
U:=Σ(Σ(script('u,[[],[i,j]])*𝐝.i*𝐝.j, i,1..dim), j,1..dim)
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
Definition 1
We say that the scalar product is associative if the tensor
equation holds:
Y = Y
U U
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.
axiom
ω:𝐋 := _
( Y I ) / _
U - _
( I Y ) / _
U;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
Definition 2
An algebra with a non-degenerate associative scalar product
is called a [Frobenius Algebra]?.
The Cartan-Killing Trace
axiom
Ú:=
( Y Λ ) / _
( Y I ) / _
V
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
Ù:=
( Λ Y ) / _
( I Y ) / _
V
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
test(Ù=Ú)
Type: Boolean
forms a non-degenerate associative scalar product for Y
axiom
Ũ := Ù
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
test
( Y I ) /
Ũ =
( I Y ) /
Ũ
Type: Boolean
The scalar product must be non-degenerate:
axiom
Ů:=determinant Ξ(Ξ(retract((𝐞.i * 𝐞.j)/Ũ), j,1..dim), i,1..dim)
Type: Expression(Integer)
axiom
factor(numer Ů)/factor(denom Ů)
Type: Fraction(Factored(SparseMultivariatePolynomial
?(Integer,
Kernel(Expression(Integer)))))
Definition 3
Co-scalar product (pairing)
Solve the [Snake Relation]? as a system of linear equations.
axiom
mU:=inverse matrix Ξ(Ξ(retract((𝐞.i*𝐞.j)/Ũ), i,1..dim), j,1..dim)
Type: Union(Matrix(Expression(Integer)),...)
axiom
Ω:=Σ(Σ(mU(i,j)*(𝐞.i*𝐞.j), i,1..dim), j,1..dim);
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
ΩX:=Ω/X;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
Check "dimension" and the snake relations.
axiom
d:𝐋:=
Ω /
Ũ
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
test
( I ΩX ) /
( Ũ I ) = I
Type: Boolean
axiom
test
( ΩX I ) /
( I Ũ ) = I
Type: Boolean
Definition 4
Co-algebra
Compute the "three-point" function and use it to define co-multiplication.
axiom
W:=(Y I) / Ũ;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
Cartan-Killing co-multiplication
axiom
λ:= _
( I ΩX ) / _
( Y I ) ;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
test
( ΩX I ) /
( I Y ) = λ
Type: Boolean
Frobenius Condition (fork)
axiom
H := Y / λ;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
test
( λ I ) /
( I Y ) = H
Type: Boolean
axiom
test
( I λ ) /
( Y I ) = H
Type: Boolean
The Cartan-Killing form makes H of the Frobenius condition idempotent
axiom
test( H=H/H )
Type: Boolean
Handle
axiom
Φ := λ / Y;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
The Cartan-Killing form makes Φ of the identity
axiom
test( Φ=I )
Type: Boolean
Definition 5
Unit
axiom
e:=𝐞.1
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
test
e /
λ = ΩX
Type: Boolean
Co-unit
axiom
d:=
( e I ) /
Ũ
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
test
Y /
d = Ũ
Type: Boolean
Figure 12
axiom
ΩXΩ:= ΩX * Ω;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
YXY:= Y * XY;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
arity(ΩXΩ)
Type: ClosedProp
?(ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer)))
axiom
φφ := ΩXΩ / (I X I ) / YXY;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
φφ1:=map((x:ℚ):ℚ+->numer x,φφ)
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
φφ2:=denom(ravel(φφ).1)
Type: SparseMultivariatePolynomial
?(Integer,
Kernel(Expression(Integer)))
axiom
test(φφ=(1/φφ2)*φφ1)
Type: Boolean
For Cartan-Killing this is just the co-scalar
axiom
test(φφ=Ω)
Type: Boolean
axiom
test((e,e)/H=Ω)
Type: Boolean
Bi-algebra conditions
axiom
ΦΦ:= _
( λ λ ) / _
( I I X ) / _
( I X I ) / _
( YXY ) ;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
axiom
test((e,e)/ΦΦ=φφ)
Type: Boolean
axiom
test(ΦΦ=H/H)
Type: Boolean
axiom
test(ΦΦ/(d,d)=Ũ)
Type: Boolean
axiom
test(H/(d,d)=Ũ)
Type: Boolean