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Edit detail for Snake Relation revision 10 of 11

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Editor: test1
Time: 2013/04/23 19:43:07 GMT+0
Note:

changed:
-)library MONAL PROP LIN
)library MONAL PROP LOP

changed:
-𝐋 := LinearOperator(dim, OVAR [], ℚ)
-𝐞:ℒ 𝐋      := basisVectors()
-𝐝:ℒ 𝐋      := basisForms()
𝐋 := LinearOperator(OVAR ['1, '2], ℚ)
𝐞:ℒ 𝐋      := basisOut()
𝐝:ℒ 𝐋      := basisIn()

Non-degeneracy of the pairing

Ref:


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We use the Axiom LinearOperator? library

fricas
)library MONAL PROP LOP
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

and convenient notation

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

Let 𝐋 be the domain of 2-dimensional linear operators

fricas
dim:=2

\label{eq1}2(1)
Type: PositiveInteger?
fricas
macro ℒ == List
Type: Void
fricas
macro ℚ == Expression Integer
Type: Void
fricas
𝐋 := LinearOperator(OVAR ['1, '2], ℚ)

\label{eq2}\hbox{\axiomType{LinearOperator}\ } (\hbox{\axiomType{OrderedVariableList}\ } ([ 1, 2 ]) , \hbox{\axiomType{Expression}\ } (\hbox{\axiomType{Integer}\ }))(2)
Type: Type
fricas
𝐞:ℒ 𝐋      := basisOut()

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

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

\label{eq5}{|_{1}^{1}}+{|_{2}^{2}}(5)
Type: LinearOperator?(OrderedVariableList?([1,2]),Expression(Integer))
fricas
X:𝐋:=[2,1] -- twist

\label{eq6}{|_{1 \  1}^{1 \  1}}+{|_{2 \  1}^{1 \  2}}+{|_{1 \  2}^{2 \  1}}+{|_{2 \  2}^{2 \  2}}(6)
Type: LinearOperator?(OrderedVariableList?([1,2]),Expression(Integer))

Pairing

A scalar product (pairing) is represented by

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

\label{eq7}{{u^{1, \: 1}}\ {|_{\ }^{1 \  1}}}+{{u^{1, \: 2}}\ {|_{\ }^{1 \  2}}}+{{u^{2, \: 1}}\ {|_{\ }^{2 \  1}}}+{{u^{2, \: 2}}\ {|_{\ }^{2 \  2}}}(7)
Type: LinearOperator?(OrderedVariableList?([1,2]),Expression(Integer))

In general we do not require that it be symmetric.

Co-pairing

Solve the "snake relation" as a system of linear equations.

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Ω:𝐋:=Σ(Σ(sb('u,[i,j])*𝐞.i*𝐞.j, i,1..dim), j,1..dim)

\label{eq8}{{u_{1, \: 1}}\ {|_{1 \  1}}}+{{u_{1, \: 2}}\ {|_{1 \  2}}}+{{u_{2, \: 1}}\ {|_{2 \  1}}}+{{u_{2, \: 2}}\ {|_{2 \  2}}}(8)
Type: LinearOperator?(OrderedVariableList?([1,2]),Expression(Integer))
fricas
Í:=(I*Ω)/(U*I);
Function: contract : (Integer,%,Integer,%,Integer) -> % is missing from domain: CartesianTensor(1,2,Expression(Integer)) Internal Error The function contract with signature $(Integer)$(Integer)$(Integer) is missing from domain CartesianTensor12(Expression (Integer))

This is equivalent to a matrix inverse (transposed!)

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Um:=matrix Ξ(Ξ((𝐞.i*𝐞.j)/U, i,1..dim), j,1..dim)
Function: contract : (Integer,%,Integer,%,Integer) -> % is missing from domain: CartesianTensor(1,2,Expression(Integer)) Internal Error The function contract with signature $(Integer)$(Integer)$(Integer) is missing from domain CartesianTensor12(Expression (Integer))

Check that the snake relation holds

fricas
test
    (  I Ω   )  /
    (   U I  )  =  I
Function: contract : (Integer,%,Integer,%,Integer) -> % is missing from domain: CartesianTensor(1,2,Expression(Integer)) Internal Error The function contract with signature $(Integer)$(Integer)$(Integer) is missing from domain CartesianTensor12(Expression (Integer))

Dimension

This quantity depends on U!


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fricas
d:=
    Ω /
    U
Function: contract : (Integer,%,Integer,%,Integer) -> % is missing from domain: CartesianTensor(1,2,Expression(Integer)) Internal Error The function contract with signature $(Integer)$(Integer)$(Integer) is missing from domain CartesianTensor12(Expression (Integer))

This "twisted" quantity does not.


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fricas
d':=
     Ω /
     X /
     U
Function: contract : (Integer,%,Integer,%,Integer) -> % is missing from domain: CartesianTensor(1,2,Expression(Integer)) Internal Error The function contract with signature $(Integer)$(Integer)$(Integer) is missing from domain CartesianTensor12(Expression (Integer))

Symmetric Pairing

Repeat the calculation, assuming that U is symmetric.

fricas
sym:=groebner ravel(U-X/U)
Function: contract : (Integer,%,Integer,%,Integer) -> % is missing from domain: CartesianTensor(1,2,Expression(Integer)) Internal Error The function contract with signature $(Integer)$(Integer)$(Integer) is missing from domain CartesianTensor12(Expression (Integer))

fricas
Um:=matrix Ξ(Ξ((𝐞.i*𝐞.j)/U, i,1..dim), j,1..dim)
Function: contract : (Integer,%,Integer,%,Integer) -> % is missing from domain: CartesianTensor(1,2,Expression(Integer)) Internal Error The function contract with signature $(Integer)$(Integer)$(Integer) is missing from domain CartesianTensor12(Expression (Integer))

Check that the snake relation holds

fricas
test
    (  I Ω   )  /
    (   U I  )  =  I
Function: contract : (Integer,%,Integer,%,Integer) -> % is missing from domain: CartesianTensor(1,2,Expression(Integer)) Internal Error The function contract with signature $(Integer)$(Integer)$(Integer) is missing from domain CartesianTensor12(Expression (Integer))

These quantities no longer depends on U!

fricas
d:=
    Ω /
    U
Function: contract : (Integer,%,Integer,%,Integer) -> % is missing from domain: CartesianTensor(1,2,Expression(Integer)) Internal Error The function contract with signature $(Integer)$(Integer)$(Integer) is missing from domain CartesianTensor12(Expression (Integer))

fricas
d':=
     Ω /
     X /
     U
Function: contract : (Integer,%,Integer,%,Integer) -> % is missing from domain: CartesianTensor(1,2,Expression(Integer)) Internal Error The function contract with signature $(Integer)$(Integer)$(Integer) is missing from domain CartesianTensor12(Expression (Integer))

Twist dimension or twist snake? --Bill Page, Sun, 08 May 2011 14:16:39 -0700 reply
TwistedSnakeRelation?