Hello everyone
I have been trying to write a thorn to couple the Klein-Gordon equations to the 3+1 Einstein equations. I can't figure out the details on how to make the thorn tell the ET how to update T_munu according to the evolution equations. I've been trying to write the thorn with Kranc without much luck, as Kranc isn't telling me anything when it does fail. I have attached the .m of the attempted thorn here. If anyone has any input or suggestions it would be greatly appreciated.
Nicholas Olsen
Nicholas
Are you writing your thorn via Kranc, or are you writing it in C/C++/Fortran?
There is a schedule group "AddToTmunu". You should schedule a routine there that modifies (adds to) the Tmunu variables, as there might be several sources of stress-energy. Particular to Kranc, you will need to (a) determine how to access the Tmumu variables, and (b) set up the correct scheduling to ensure that the routine is called at the right time.
If you are looking for details then we can schedule a Zoom call to discuss.
-erik
On Mon, Feb 7, 2022 at 12:50 PM Nick Olsen n.olsen.3.711@gmail.com wrote:
Hello everyone
I have been trying to write a thorn to couple the Klein-Gordon equations to the 3+1 Einstein equations. I can't figure out the details on how to make the thorn tell the ET how to update T_munu according to the evolution equations. I've been trying to write the thorn with Kranc without much luck, as Kranc isn't telling me anything when it does fail. I have attached the .m of the attempted thorn here. If anyone has any input or suggestions it would be greatly appreciated.
Nicholas Olsen _______________________________________________ Users mailing list Users@einsteintoolkit.org http://lists.einsteintoolkit.org/mailman/listinfo/users
hi Nick,
i can't really help you out with Kranc, but we have a freely available thorn that does precisely the Einstein-Klein-Gordon system. you can find it here as part of the Canuda library: https://bitbucket.org/canuda/scalar/src/master/ i hope it helps.
cheers, Miguel
On 07/02/2022 17:50, Nick Olsen wrote:
Hello everyone
I have been trying to write a thorn to couple the Klein-Gordon equations to the 3+1 Einstein equations. I can't figure out the details on how to make the thorn tell the ET how to update T_munu according to the evolution equations. I've been trying to write the thorn with Kranc without much luck, as Kranc isn't telling me anything when it does fail. I have attached the .m of the attempted thorn here. If anyone has any input or suggestions it would be greatly appreciated.
Nicholas Olsen
Users mailing list Users@einsteintoolkit.org http://lists.einsteintoolkit.org/mailman/listinfo/users
Thanks for the quick responses Erik and Miguel
To answer Erik's question, I intended to use Kranc as a simpler way to write the thorn and if the roadblocks didn't stop I was going to switch to manually writing the thorn using one of the hydrodynamic thorns as a skeleton framework to learn how to write a thorn for coupled equations, which is roughly where I was today if Kranc wasn't an easy fix. I will have to get back to you on your offer after I read through what Miguel has linked here thoroughly, but thank you for the offer.
Miguel, I believe I will need some time to take an in depth look at this before I can be sure that this is what I have been looking for, but I suspect it is exactly what I need, so thank you very much for this.
Nicholas Olsen
On Mon, Feb 7, 2022 at 1:51 PM Miguel Zilhão mzilhao@ua.pt wrote:
hi Nick,
i can't really help you out with Kranc, but we have a freely available thorn that does precisely the Einstein-Klein-Gordon system. you can find it here as part of the Canuda library: https://bitbucket.org/canuda/scalar/src/master/ i hope it helps.
cheers, Miguel
On 07/02/2022 17:50, Nick Olsen wrote:
Hello everyone
I have been trying to write a thorn to couple the Klein-Gordon equations
to the 3+1 Einstein
equations. I can't figure out the details on how to make the thorn tell
the ET how to update T_munu
according to the evolution equations. I've been trying to write the
thorn with Kranc without much
luck, as Kranc isn't telling me anything when it does fail. I have
attached the .m of the attempted
thorn here. If anyone has any input or suggestions it would be greatly
appreciated.
Nicholas Olsen
Users mailing list Users@einsteintoolkit.org http://lists.einsteintoolkit.org/mailman/listinfo/users
users@lists.einsteintoolkit.org
-
Erik Schnetter -
Miguel Zilhão -
Nick Olsen