Hi,

On Tue, Mar 07, 2017 at 12:11:50PM +0200, Gwyneth Allwright wrote:

I'm aware that one can use the thorns Meudon_Bin_BH, Meudon_Bin_NS and Meudon_Mag_NS to import data from LORENE for binary black holes, binary neutron stars and magnetized neutron stars respectively. Are there any thorns for black-hole-neutron-star binaries?

Lorene is used as library, which means you can pick components and combine them as you like. So, generating BHNS initial data should be possible, and if I remember correctly, has been done. Classes for this exist in Lorene, and I remember possibly more than one. However, I say should because I couldn't point you to something specific right now.

Even if you succeed with that, you would need to import these data into the toolkit. This in principle isn't a difficult task: you evaluate the Lorene data on the Carpet grid, using the same Lorene C++ classes that were used to generate the data (simplified speaking, some variables might have to be converted as well). Lorene already has functions for this evaluation, what is missing could be called 'bookkeeping and conversion'. The Einstein Toolkit does not contain thorns that do that (interface to the BHNS classes in Lorene). Once you managed to get ID, it shouldn't be difficult to take one of the existing thorns, make a copy, and change what would need to be changed. It might not be a lot.

I know this is probably not what you wanted to read, but the state of BHNS initial data isn't the best, neither in (public) Lorene initial data, even less in public and current parameter files for Lorene, and because of that, also not for importing those data into the Einstein Toolkit.

Frank