If I enter ex:= -\frac{2}{3} \indexbracket{ (\theta \Gamma_{m} \chi2)};

XCadabra 1.39 (on Linux 16.04) shows above without the factor of -2/3 . How to get this factor?

0 votes

You may want to upgrade to 2.x, where this works fine. If you can't do that, can you explain what is stopping you? (e.g. some feature which is broken/missing in 2.x but working in 1.x).

I tried my problem in 2.x but couldn't continue because of the issue with combine algorithm. I asked about these here,

https://cadabra.science/qa/687/combine-algorith-for-gamma-matrices and https://cadabra.science/qa/667/possible-issue-with-combine-algorithm

It would be great if these are fixed.

Thanks