<div dir="ltr">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.</div><div id="DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br>
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</table><a href="#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2" width="1" height="1"></a></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Nov 7, 2017 at 8:31 PM, Ian Hinder <span dir="ltr"><<a href="mailto:ian.hinder@aei.mpg.de" target="_blank">ian.hinder@aei.mpg.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word"><br><div><span class=""><div>On 7 Nov 2017, at 14:04, Nisa Amir <<a href="mailto:nisaamir@math.qau.edu.pk" target="_blank">nisaamir@math.qau.edu.pk</a>> wrote:</div><br class="m_5533839742229299924Apple-interchange-newline"><blockquote type="cite"><div dir="ltr">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?</div></blockquote><div><br></div></span><div>Hi,</div><div><br></div><div>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.</div><div><br></div><div>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?</div><div><br></div><div>Thanks!</div><div><br></div></div><span class=""><div>
<div style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word"><div style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word"><div style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word"><div style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word"><div>-- </div><div>Ian Hinder</div><div><a href="http://members.aei.mpg.de/ianhin" target="_blank">http://members.aei.mpg.de/<wbr>ianhin</a></div></div></div></div></div>
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