[Users] [Fwd: Kerr ID]

[Scott Noble]

Ok, here is the maple script that verifies my derivation of shift_phi .

Please commit it to the proper location.

Erik Schnetter wrote:
> On Wed, Oct 6, 2010 at 8:45 PM, Scott Noble <scn at astro.rit.edu> wrote:
>> Hello Erik and Bruno,
>>
>>  I do not know off-hand a place in the literature where \beta^\phi is
>> stated.  \beta^\phi in BL coordinates is rarely expressed since the BL
>> metric is usually given in line element form, not in ADM form.
>>
>>  It should be simple enough to derive it from the other components, which
>> (IMHO) are correct.   I could make a maple script that derives it, but then
>> you'd have to trust that I wrote up the maple script correctly...
> 
> Either we trust you, or you could commit the Maple script (in ASCII
> form so that it is easily readable) to the documentation.
> 
>>  FYI: I believe
>>
>>  shift_phi = \beta^\phi    and
>>  beta_phi = \beta_\phi    .
> 
> Yes, that makes sense! I was puzzled about that difference and didn't
> think of a lowered index.
> 
>> -- scott n.
>>
>>
>> On 10/6/10 8:29 PM, Bruno Coutinho Mundim wrote:
>>> Hi Scott and Erik,
>>>
>>> I was also looking into this issue now. The mapping from the PRD 54 1403
>>> paper to the code documentation seems to go as in:
>>>
>>> Paper Documentation
>>> r r_k
>>> \bar{r} r
>>> quasi-isotropic radius \eta ???
>>>
>>> Also note that the Sigma definition in the documentation is not the
>>> usual definition in Boyer-Lindquist coordinates.
>>>
>>> I hope there is a reference for the documentation. Otherwise, the
>>> non-usual notation there prevents us of a simple check.
>>>
>>> Thanks,
>>> Bruno.
>>>
>>> Erik Schnetter wrote:
>>>> Scott
>>>>
>>>> Do you have a pointer to literature that contains the correct
>>>> equation? I'm looking at PRD 54 1403, which is the paper cited in the
>>>> thorn; is that a good choice? Do you know how the variables in the
>>>> paper are mapped to the variables in the code? The code documentation
>>>> (the latex file doc/documentation.tex) seems consistent with the C
>>>> code, but of course both could be wrong. Or is there an easy way to
>>>> see why the factor Sigma is missing?
>>>>
>>>> I haven't used the Boyer-Lindquist Kerr initial data implemented in
>>>> this thorn myself; I usually use Kerr-Schild coordinates form thorn
>>>> Exact.
>>>>
>>>> -erik
>>>>
>>>> On Wed, Oct 6, 2010 at 11:18 AM, Scott Noble <scn at astro.rit.edu> wrote:
>>>>> I see that this has not been patched yet. Can someone please confirm the
>>>>> fix and
>>>>> patch the repo?
>>>>>
>>>>> thanks, scott n.
>>>>>
>>>>>
>>>>> -------- Original Message --------
>>>>> Subject: Kerr ID
>>>>> Date: Mon, 07 Jun 2010 16:54:20 -0400
>>>>> From: Scott Noble <scn at astro.rit.edu>
>>>>> To: users at einsteintoolkit.org
>>>>>
>>>>>
>>>>> Hello Users,
>>>>>
>>>>>
>>>>> I believe I found a minor typo in
>>>>>
>>>>> EinsteinInitialData/IDAnalyticBH/src/Kerr.c
>>>>>
>>>>> of the ET. Just a missing term in the denominator of the shift
>>>>> vector, so
>>>>> it will not likely affect many users. I have attached a patch.
>>>>>
>>>>> cheers,
>>>>>
>>>>> -- scott n.
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Users mailing list
>>>>> Users at einsteintoolkit.org
>>>>> http://lists.einsteintoolkit.org/mailman/listinfo/users
>>>>>
>>>>>
>>>>
>>>>
> 
> 
> 
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