[Users] error when I trying to add atmosphere to BBH evolution

[赵志超]

Thank you Roland,

https://arxiv.org/abs/1704.07383 is exactly what I want to repeat.

Thank you for you help, I will contact the 1st author for help of your
paper if I failed.

Best Wishes.

Yours,
Zhi-Chao.


2017-08-18 23:44 GMT+08:00 Roland Haas <roland.haas at physics.gatech.edu>:

> Hello all,
>
> > Could you give more details about the physics you are trying to add?
> > "atmosphere" in this context usually means an artificial low density
> > fluid in a matter simulation which helps with numerical problems that
> > occur when the density drops to zero.  It doesn't make sense to add
> > it to a BBH simulation, which is vacuum.
> >
> > Do you mean that you want to add a low density fluid to a BBH
> > simulation?
> In case you are planning something similar to
> https://arxiv.org/abs/1704.07383 then you may want to contact the first
> author (Joseph Fedrow) possibly through this list (he's subscribed).
> Typically you will get failures of con2prim near the punctures and have to
> take special measures to work around it.
>
> Usually this involves setting
>
> * GRHydro::recon_method = ppm # since it is very robust
> * GRHydro::reconstruct_Wv = yes # avoids some v^2>c^2 situations
> * GRHydro::riemann_solver = "Marquina" # better than HLLE for this
> * GRHydro::sqrtdet_thr = 10. # or so, these apply Joshua Faber's
>   methods described in https://arxiv.org/abs/0708.2436
> * GRhydro::c2p_resort_to_bisection = yes # try bisection if
>   Newton-Raphson iteration fails
>
> Note that my recollection of the paper by Fedrow (I am a co-author) was
> that all of those were required but not quite enough and that Christian
> Ott had to write a special con2prim routine that handled the BH interior
> carefully.
>
> There is a also code in TwoPunctures that can solve the constraints
> (the TP code is in the ET but not the code that eg provides a density
> profile). Again best would be to contact the authors (all reachable
> through this list).
>
> Yours,
> Roland
>
> --
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>



-- 
赵志超
中国科学院高能物理研究所
中国 北京
18401696963
yanyuechuixue at gmail.com
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