[Users] recon_method dependency (weno)

Hee Il Kim heeilkim at gmail.com
Thu Jun 10 16:52:20 CDT 2021


Thanks Roland and Maria

2021년 6월 10일 (목) 오후 11:50, Roland Haas <rhaas at illinois.edu>님이 작성:

> Hello Hee Il,
>
> from your email it seems that you are seeing differences between
> different ET releases but with the same par file.
>

I'm not seeing different results between Turing and Lorentz. Since they are
identical, I've shown only representative plots (rhomax vs time btw). The
issue is that he WENO of the ET versions do not produce the same
inspiraling time with that of WENO-Z, MP5, and PPM, whereas the other three
recon methods show decent coincidence for the inspiralling time.


> Yet your plot seems to not show any pair of curves that only differ by
> the release code used.
>

Explained above.


>
> If you are comparing to the runs by the Parma group (or any
> simulation) then you must ensure that you are comparing "apples with
> apples" ie you would have to run their parfiles with the current ET
> release (to check for a change) and also with their code (to check if
> the issue is compiler / cluster changes).
>
>
I'm not going to compare my current results to the Parma group runs. As you
discussed in the meeting, since they used the recon codes and Con2Prim for
the MHD, it might give different results. But if the differences are big
even with zero B, I think it needs to be examined further in the future.


> They provide their code and parfiles in:
>
> https://einstein.pr.infn.it/svn/numrel/pub/
>
> See "Background material" on
>
> https://einstein.pr.infn.it/gravity/Research/BNS2016.html
>
> which is listed on the "Additional Resources" page of:
>
> https://docs.einsteintoolkit.org/et-docs/Additional_resources
>
> Yours,
> Roland
>

I've been aware of it and used its grid setup. At first, I didn't follow
their parfile but used my own grid amr with NSTracker. But for the
comparison, I followed the parfiles there. I haven't tried to use the
entire code of the Parma group. But at least I found their Lorene is
different from official Lorene and ET Lorenes. I've made an ID by using
their Lorene but the ID was not readable by recent ET/GRHydros.

My feeling is that GRHydro_WenoRecontruct codes need to be examined.

Thanks,

Hee Il


> > Hi
> >
> > I'm reporting on recon_method dependency issue at least found in Turing
> and
> > Lorentz. I've been studying BNS evolution by taking some of the Parma
> group
> > models as references (DOI: 10.1103/PhysRevD.93.064047). But there were
> > significant differences in merger time, t_merger. At the moment, I will
> put
> > aside direct comparison between the GRHydro of Parma and recents ones.
> >
> > What I've found is that WENO of Turing/Lorentz produces much shorter
> > inspiraling time (See the attached figure). But WENO-Z/PPM/MP5, they all
> > produce similar inspiraling time. Of course, depending on resolutions,
> they
> > produce different merging behaviour but as shown in the figure,
> higher-res
> > PPM matches with lower-res WENO-Z nicely, which is consistent with our
> > expectations. I've got the identical results for both Turing and Lorentz
> > versions.
> >
> > I've missed recent GRHydro developments for a long time and I have no
> > guesses for the discrepancy. I hope GRHydro developers examine this issue
> > for the consistency of the recon_method. Thanks for your help in advance.
> >
> > Hee Il
>
>
> --
> My email is as private as my paper mail. I therefore support encrypting
> and signing email messages. Get my PGP key from http://pgp.mit.edu .
>
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