[Users] About the thorn Einstein exact

[Nisa Amir]

I am just trying to add this spacetime, I dont want to use it in some other
thorns of the toolkit. and I am not familiar with xAct package.

<https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon>
Virus-free.
www.avast.com
<https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link>
<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

On Tue, Nov 7, 2017 at 8:31 PM, Ian Hinder <ian.hinder at aei.mpg.de> wrote:

>
> On 7 Nov 2017, at 14:04, Nisa Amir <nisaamir at math.qau.edu.pk> wrote:
>
> Yes, the mathematica package is given but it accepts the metric only in
> cartesian coordinates. I want to add the spacetime non kerr which is in
> polar coordinates to the mathematica package in Einstein Exact thorn. What
> transformations should I made?
>
>
> Hi,
>
> You can apply the usual basis transformations in Mathematica to generate
> the metric in a quasi-Cartesian basis and coordinates.  This will then
> allow you to construct the spacetime numerically in these coordinates, and
> the thorns in the toolkit which expect quasi-Cartesian coordinates will
> just work, for example the horizon finder.  You would then evolve in 3+1
> dimensions.  I have done this for Kerr in Boyer-Lindquist coordinates using
> the xAct tensor manipulation package.  This is not straightforward, and
> it's not something that I would take on lightly if you don't have much
> experience with EinsteinExact or xAct.
>
> However, you have said that you want to store the gridfunctions in polar
> coordinates, and do the evolution in polar coordinates.  I have no
> experience with this, and many of the thorns in the toolkit which expect
> quasi-Cartesian coordinates will just not work (e.g. the horizon finder).
> That is why I asked you what you are trying to do.  Please can you answer
> that, before we go into a lot of detail about how to do it in one
> particular way, which may in the end not help you?
>
> Thanks!
>
> --
> Ian Hinder
> http://members.aei.mpg.de/ianhin
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.einsteintoolkit.org/pipermail/users/attachments/20171107/1773c7b8/attachment-0001.html