<html>#2160: QuasiLocalMeasures qlm_spin doesn't work for spins not aligned along the z axis
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<tr><td style='text-align:right'> Reporter:</td><td></td></tr>
<tr><td style='text-align:right'> Status:</td><td>new</td></tr>
<tr><td style='text-align:right'>Milestone:</td><td></td></tr>
<tr><td style='text-align:right'> Version:</td><td>development version</td></tr>
<tr><td style='text-align:right'> Type:</td><td>bug</td></tr>
<tr><td style='text-align:right'> Priority:</td><td>minor</td></tr>
<tr><td style='text-align:right'>Component:</td><td>EinsteinToolkit thorn</td></tr>
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<p>Comment (by Roland Haas):</p>
<p>A similar question was asked on the mailing list and responded to in <a data-is-external-link="true" href="http://lists.einsteintoolkit.org/pipermail/users/2021-April/007931.html" rel="nofollow">http://lists.einsteintoolkit.org/pipermail/users/2021-April/007931.html</a> with:</p>
<blockquote>
<p>QuasiLocalMeasures regular spin measurement assumes that the black hole<br />
spin is roughly aligned with the z direction. A spin near the equatorial<br />
plane does not work well. In this case you'll have to use the coordinate<br />
spins (qlm_coordspinx, qlm_coordspiny, qlm_coordspinz); these are less<br />
accurate for distorted black holes, but will still work very well under<br />
these circumstances.</p>
</blockquote>
<p>so the Killing vector method was only ever designed to work with spins more or less along the z-direction and changing the method to compute the Killing vector will not help.</p>
<p>--<br/>
Ticket URL: <a href='https://bitbucket.org/einsteintoolkit/tickets/issues/2160/quasilocalmeasures-qlm_spin-doesnt-work'>https://bitbucket.org/einsteintoolkit/tickets/issues/2160/quasilocalmeasures-qlm_spin-doesnt-work</a></p>
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