<html>#2300: Update: Add Piecewise Polytrope EoS Support to IllinoisGRMHD, Improved TOV Solver?
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<tr><td style='text-align:right'> Reporter:</td><td>Zach Etienne</td></tr>
<tr><td style='text-align:right'> Status:</td><td>new</td></tr>
<tr><td style='text-align:right'>Milestone:</td><td>ET_2020_04</td></tr>
<tr><td style='text-align:right'> Version:</td><td></td></tr>
<tr><td style='text-align:right'> Type:</td><td>enhancement</td></tr>
<tr><td style='text-align:right'> Priority:</td><td>major</td></tr>
<tr><td style='text-align:right'>Component:</td><td></td></tr>
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<h1 id="markdown-header-piecewise-polytrope-equation-of-state-support-in-illinoisgrmhd">Piecewise-Polytrope Equation of State Support in IllinoisGRMHD</h1>
<p>Leonardo (Leo) Werneck (a student currently working in my research group) recently documented much of <code>IllinoisGRMHD</code> in Jupyter notebooks and worked with me to add piecewise-polytrope equation of state support to <code>IllinoisGRMHD</code>. The code is open-source and available here:</p>
<p><a data-is-external-link="true" href="https://github.com/zachetienne/nrpytutorial/tree/master/IllinoisGRMHD/doc" rel="nofollow">https://github.com/zachetienne/nrpytutorial/tree/master/IllinoisGRMHD/doc</a></p>
<p>In addition, the Jupyter notebooks may be browsed via nbviewer:</p>
<p><a data-is-external-link="true" href="https://nbviewer.jupyter.org/github/zachetienne/nrpytutorial/tree/master/IllinoisGRMHD/doc/" rel="nofollow">https://nbviewer.jupyter.org/github/zachetienne/nrpytutorial/tree/master/IllinoisGRMHD/doc/</a></p>
<p>The updated code agrees to roundoff error with the original <code>IllinoisGRMHD</code> when a single polytrope is chosen, and the central density vs time when evolving piecewise-polytrope TOV stars (we tried the APR4 piecewise-polytrope as described in Read et al.) converges to zero density drift a bit above 2nd order with increased resolution, just like in the single-polytrope case. Further, we have successfully evolved SLy piecewise polytrope BNS initial data through a couple orbits (so far).</p>
<p>One can generate the new piecewise-polytrope enabled <code>IllinoisGRMHD</code> thorn family by cloning the above github repo and running the <code>generate_illinoisgrmhd_from_ipynb_files.sh</code> script in that directory. The <code>IllinoisGRMHD/test</code> directory contains some example parameter files.</p>
<h2 id="markdown-header-piecewise-polytrope-tov-solver">Piecewise-Polytrope TOV Solver?</h2>
<p>To perform the above piecewise-polytrope TOV tests, we needed a simple TOV solver with this capability (<code>TOVSolver</code> only supp
<p>--<br/>
Ticket URL: <a href='https://bitbucket.org/einsteintoolkit/tickets/issues/2300/update-add-piecewise-polytrope-eos-support'>https://bitbucket.org/einsteintoolkit/tickets/issues/2300/update-add-piecewise-polytrope-eos-support</a></p>
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