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.
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(1) -> )library CARTEN ARITY CMONAL CPROP CLOP CALEY
CartesianTensor is now explicitly exposed in frame initial
CartesianTensor will be automatically loaded when needed from
/var/aw/var/LatexWiki/CARTEN.NRLIB/CARTEN
Arity is now explicitly exposed in frame initial
Arity will be automatically loaded when needed from
/var/aw/var/LatexWiki/ARITY.NRLIB/ARITY
ClosedMonoidal is now explicitly exposed in frame initial
ClosedMonoidal will be automatically loaded when needed from
/var/aw/var/LatexWiki/CMONAL.NRLIB/CMONAL
ClosedProp is now explicitly exposed in frame initial
ClosedProp will be automatically loaded when needed from
/var/aw/var/LatexWiki/CPROP.NRLIB/CPROP
ClosedLinearOperator is now explicitly exposed in frame initial
ClosedLinearOperator will be automatically loaded when needed from
/var/aw/var/LatexWiki/CLOP.NRLIB/CLOP
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
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-- summation
macro Σ(x,i,n)==reduce(+,[x for i in n])
Type: Void
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-- list
macro Ξ(f,i,n)==[f for i in n]
Type: Void
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-- subscript and superscripts
macro sb == subscript
Type: Void
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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.
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dim:=8
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macro ℒ == List
Type: Void
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macro ℂ == CaleyDickson
Type: Void
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macro ℚ == Expression Integer
Type: Void
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𝐋 := ClosedLinearOperator(OVAR ['1,'i,'j,'k,'ij,'ik,'jk,'ijk], ℚ)
Type: Type
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𝐞:ℒ 𝐋 := basisOut()
Type: List(ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer)))
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𝐝:ℒ 𝐋 := basisIn()
Type: List(ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer)))
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I:𝐋:=[1] -- identity for composition
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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X:𝐋:=[2,1] -- twist
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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V:𝐋:=ev(1) -- evaluation
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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Λ:𝐋:=co(1) -- co-evaluation
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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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
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q0:=sp('i,[2])
Type: Symbol
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q1:=sp('j,[2])
Type: Symbol
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q2:=sp('k,[2])
Type: Symbol
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QQ:=CliffordAlgebra(3,ℚ,matrix [[q0,0,0],[0,q1,0],[0,0,q2]])
Type: Type
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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),
[[i[;2],
0,
0],
[0,
j[;2],
0],
[0,
0,
k[;2]]]))
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M:Matrix QQ := matrix Ξ(Ξ(B.i*B.j, i,1..dim), j,1..dim)
Type: Matrix(CliffordAlgebra
?(3,
Expression(Integer),
[[i[;2],
0,
0],
[0,
j[;2],
0],
[0,
0,
k[;2]]]))
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S(y) == map(x +-> coefficient(recip(y)*x,[]),M)
Type: Void
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ѕ :=map(S,B)::ℒ ℒ ℒ ℚ
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Compiling function S with type CliffordAlgebra(3,Expression(Integer)
,[[i[;2],0,0],[0,j[;2],0],[0,0,k[;2]]]) -> Matrix(Expression(
Integer))
Type: List(List(List(Expression(Integer))))
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-- 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))
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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)))
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XY := X/Y;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
Multiplication is Associative
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test(
( I Y ) / _
( Y ) = _
( Y I ) / _
( Y ) )
Type: Boolean
A scalar product is denoted by the (2,0)-tensor
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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.
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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
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Ú:=
( Y Λ ) / _
( Y I ) / _
V
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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Ù:=
( Λ Y ) / _
( I Y ) / _
V
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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test(Ù=Ú)
Type: Boolean
forms a non-degenerate associative scalar product for Y
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Ũ := Ù
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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test
( Y I ) /
Ũ =
( I Y ) /
Ũ
Type: Boolean
The scalar product must be non-degenerate:
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Ů:=determinant Ξ(Ξ(retract((𝐞.i * 𝐞.j)/Ũ), j,1..dim), i,1..dim)
Type: Expression(Integer)
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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.
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mU:=inverse matrix Ξ(Ξ(retract((𝐞.i*𝐞.j)/Ũ), i,1..dim), j,1..dim)
Type: Union(Matrix(Expression(Integer)),...)
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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))
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ΩX:=Ω/X;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
Check "dimension" and the snake relations.
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d:𝐋:=
Ω /
Ũ
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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test
( I ΩX ) /
( Ũ I ) = I
Type: Boolean
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test
( ΩX I ) /
( I Ũ ) = I
Type: Boolean
Definition 4
Co-algebra
Compute the "three-point" function and use it to define co-multiplication.
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W:=(Y I) / Ũ;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
Cartan-Killing co-multiplication
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λ:= _
( I ΩX ) / _
( Y I ) ;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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test
( ΩX I ) /
( I Y ) = λ
Type: Boolean
Frobenius Condition (fork)
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H := Y / λ;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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test
( λ I ) /
( I Y ) = H
Type: Boolean
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test
( I λ ) /
( Y I ) = H
Type: Boolean
The Cartan-Killing form makes H of the Frobenius condition idempotent
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test( H=H/H )
Type: Boolean
Handle
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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
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test( Φ=I )
Type: Boolean
Definition 5
Unit
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e:=𝐞.1
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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test
e /
λ = ΩX
Type: Boolean
Co-unit
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d:=
( e I ) /
Ũ
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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test
Y /
d = Ũ
Type: Boolean
Figure 12
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ΩXΩ:= ΩX * Ω;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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YXY:= Y * XY;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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arity(ΩXΩ)
Type: ClosedProp
?(ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer)))
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φφ := ΩXΩ / (I X I ) / YXY;
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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φφ1:=map((x:ℚ):ℚ+->numer x,φφ)
Type: ClosedLinearOperator
?(OrderedVariableList
?([1,
i,
j,
k,
ij,
ik,
jk,
ijk]),
Expression(Integer))
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φφ2:=denom(ravel(φφ).1)
Type: SparseMultivariatePolynomial
?(Integer,
Kernel(Expression(Integer)))
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test(φφ=(1/φφ2)*φφ1)
Type: Boolean
For Cartan-Killing this is just the co-scalar
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test(φφ=Ω)
Type: Boolean
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test((e,e)/H=Ω)
Type: Boolean
Bi-algebra conditions
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ΦΦ:= _
( λ λ ) / _
( I I X ) / _
( I X I ) / _
( YXY ) ;
>> System error:
Heap exhausted (no more space for allocation).
13434880 bytes available, 134217744 requested.
PROCEED WITH CAUTION.