Problem with Contract[exp1,exp2]

[kirtimaan]

Screen shot of mathematica notebook showing the problem with Contract.

Contract[exp1,exp2] != Contract[exp2,exp1]

[vsht]

You are using wrong syntax. Contract[exp1,exp2] is meant for internal use only, not for end-users. What you should use is Contract[expr,], e.g.

Contract[(MT[a, b] FV[p, mu] FVD[q, nu] +  MT[mu, nu] FV[p, a] FV[q, b]) MT[mu, nu]]
Contract[(MT[a, b] FV[p, mu] FVD[q, nu] +  MT[mu, nu] FV[p, a] FV[q, b]) MT[a, b]]

See also https://feyncalc.github.io/FeynCalcBook/ref/Contract.html

[kirtimaan]

Thanks, This should be updated in the FeynCalc reference which states the following "Contract[exp1, exp2] contracts (exp1*exp2), where exp1 and exp2 may be larger products of sums of metric tensors and 4-vectors." --https://feyncalc.org/FeynCalcBook/Contract/index.html

[vsht]

Actually, the link that I provided is the updated reference:

https://feyncalc.github.io/reference

"FeynCalcBook" is the outdated one that is kept online for legacy reasons.

Am 21.11.2016 um 21:41 schrieb kirtimaan:

Thanks, This should be updated in the FeynCalc reference which states the following "Contract[exp1, exp2] contracts (exp1*exp2), where exp1 and exp2 may be larger products of sums of metric tensors and 4-vectors." --https://feyncalc.org/FeynCalcBook/Contract/index.html

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