GW150914 example should be updated to work with the Einstein Toolkit thornlist

[Ian Hinder]

The GW150914 example currently uses its own thornlist, because Llama was not part of the ET when it was created. Llama has now been added to the ET. The GW150914 thornlist uses WaveExtractCPM and ADMConstraints. These can probably be removed, for the sake of having a parameter file which works with the ET thornlist. ADMConstraints can be replaced with ML_ADMConstraints. WaveExtractCPM is an "in-development" code which has not been extensively tested. It gives the GW strain directly from Schwarzschild perturbation theory, without needing to go via fixed-frequency integration of Psi4, so is good for quick plots. However, it seems to give worse results than Psi4 for the ringdown, and possibly has bugs in some of the l > 2 modes, so I don't think it is ready for inclusion in the toolkit just yet.

Keyword: gallery

[Roland Haas]

WaveExtractCPM does terrible things to parameter values, namely it assigns values to parameters in Fortran code which (only in Fortran) changes the values of the Parameters circumventing CCTK_ParameterSet. Not advertising its existence is a good thing to do :-).

[Ian Hinder]

That is... disconcerting. Do WaveExtractL and WaveExtract also do this?

[Roland Haas]

yup. I have a set of fixes in 1de4c72 WaveExtractL in Llama.

[Ian Hinder]

The GW150914 example was updated to work with the ET thornlist in July 2017 in [https://bitbucket.org/einsteintoolkit/www/branches/compare/e688b4719283ff70480b25265233dc569480180c..f9f1349018d5c54945f37715e9d67f6d8807b8ef these commits].