Hi,
the option EpsContract is responsible solely for the contractions of two epsilon tensors
Contract[LC[mu, nu][p1, p2] LC[mu, nu][p3, p4]]
Contract[LC[mu, nu][p1, p2] LC[mu, nu][p3, p4], EpsContract -> False]
The contractions of 4-vectors with epsilon tensors are automatic and cannot be disabled in Contract. I wouldn't know why one would like to do that. The notation of an epsilon tensor with momenta instead of indices is standard in theoretical HEP codes (e.g. in FORM) since many years.
Cheers,
Vladyslav
Am 13.03.19 um 04:31 schrieb Timofey:
> Hello. I recently started using feyncalc for training purposes. My naive problem is that when I use the function, the Contract convolves the four-vector index and Levi-Civita, although I changed it as follows
> SetOptions [Contract, EpsContract -> False]
> and when I enter Options [Contract], EpsContract -> False is displayed. Even if I explicitly write out
> Contract[LC[\[Alpha], \[Beta], \[Mu], \[Nu]]*FV[p, \[Nu]],
> EpsContract -> False]
> it turns out \[Epsilon]^(\[Alpha]\[Beta]\[Mu]Overscript[p, _]).
> How to make the indexes do not fold with Levi-Civita? Thank you very much
This archive was generated by hypermail 2b29 : 09/04/20-12:55:05 AM Z CEST