DefProjectedTensor

[Alice Garoffolo]

Hi,

Im having trouble to define new tensors in xPand other than the metric and matter fields.

I need to define a tensor which satisfies exactly the properties of tensors defined with DefProjectedTensor (i.e. traceless, transverese and symmetric) and this I can do.

After I do this I have to contract this tensor with the Riemann tensor and expand the expression just in the metric to first order but the classical "ExpandPerturbation" doesn't work with tensors defined like mine.

How may i solve this problem? 

Thank you

Alice 

[Cyril Pitrou]

Hi,

Could you provide a miminal working example ?

Regards,

Cyril Pitrou

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[Alice Garoffolo]

Hi!

Yes, so this is part of the file I’ve been working on!

 

Thank you so much for answering so quickly!

 

Bye

 

Alice

 

Inviato da Posta per Windows 10

 

Da: Cyril Pitrou
Inviato: venerdì 8 febbraio 2019 16:04
A: Alice Garoffolo
Cc: xAct Tensor Computer Algebra
Oggetto: Re: [xAct: 2437] DefProjectedTensor