[GiNaC-list] Ordering and pattern matching
Vladimir V. Kisil
kisilv at maths.leeds.ac.uk
Tue Sep 1 13:15:42 CEST 2009
Hi, Chris,
>>>>> On Tue, 25 Aug 2009 16:12:37 +0100, Chris Kelly <giltirn at gmail.com> said:
CK> grips with the clifford algebra classes. I am trying to perform
CK> the simple substitution:
CK> A_mu gamma_mu B_nu gamma_nu = A_mu A_nu delta_mu,nu (Euclidean space).
Why you are doing this replacement? I do not think it is mathematically
correct, it shall be:
A_mu gamma_mu B_nu gamma_nu + B_nu gamma_nu A_mu gamma_mu = A_mu A_nu delta_mu,nu
You can get that answer by canonicalize_clifford() method without any
substitution.
CK> Here is some example code:
CK> ex metric = unit_matrix(4); idx i(symbol("i"),4) ,
CK> j(symbol("j"),4); ex al_i = clifford_unit(i,metric); //Use
CK> // generalised clifford gamma matrices for euclidean space
CK> //Create generic 'slashed' symbols with euclidean metric
You may prefer to use delta tensor rather than unit matrices to
create this Clifford units---output of simplification will be more
transparent.
Best wishes,
Vladimir
--
Vladimir V. Kisil email: kisilv at maths.leeds.ac.uk
-- www: http://maths.leeds.ac.uk/~kisilv/
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