Cancelling equal terms

[Pavan Dharanipragada]

Hello all,

I am replacing the metric by the metric plus a different tensor in the expression for Ricci scalar in the attached file, and trying to see the extra terms. But xAct is not cancelling equal terms, so I am left with a bunch of equal terms with opposite signs. Since the terms involve partial derivatives, I am unable to run ToCanonical on them. I am sure something simple can be done to solve this, but I am unable to see it. Please let me know your comments.

Pavan

[Thomas Bäckdahl]

Hi!

I think you can use ToCanonical. You just have to be a bit more careful.The command
SetOptions[ToCanonical, UseMetricOnVBundle -> None]
stops it from moving indices up and down.

If you don't want to use ToCanonical, you can also try Expand and ScreenDollarIndices. If you really want to see what ScreenDollarIndices is doing I would set $PrePrint =.; to avoid the automatic ScreenDollarIndices before the display. If two terms have different dollar indices, they will not cancel automatically, but ToCanonical or even ScreenDollarIndices can sort that out.

Regards
Thomas

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[Pavan Dharanipragada]

Thank you Thomas! ToCanonical worked for me.

Regards,

Pavan