<html>#2417: include PN expressions for initial momenta for BBH simualtion
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<tr><td style='text-align:right'> Reporter:</td><td>Roland Haas</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></td></tr>
<tr><td style='text-align:right'> Type:</td><td>proposal</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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<p><a data-is-external-link="true" href="https://en.wikipedia.org/wiki/Post-Newtonian_expansion" rel="nofollow">Post-Newtonian theory</a> results in some of the longest and most complex mathematical expressions ever derived by humanity.</p>
<p>These expressions form the core of most gravitational wave data analysis codes, but generally the expressions are written in a format that is either inaccessible by others (i.e., closed-source) or written directly in e.g., C code and thus incompatible with symbolic algebra packages like <a data-is-external-link="true" href="https://www.wolfram.com/mathematica/" rel="nofollow">Wolfram Mathematica</a> or the Python-based <a data-is-external-link="true" href="https://www.sympy.org/" rel="nofollow">SymPy</a>.</p>
<p>Once in a symbolic algebra package, these expressions could be manipulated, extended, and output as <em>more</em> optimized C codes (e.g., using SymPy/NRPy+, thus speeding up gravitational wave data analysis).</p>
<p>This repository aims to provide a trusted source for validated Post-Newtonian expressions useful for gravitational wave astronomy, using the open-source <a data-is-external-link="true" href="https://www.sympy.org/" rel="nofollow">SymPy</a> computer algebra system, so that expressions can be output into <a data-is-external-link="true" href="https://www.wolfram.com/mathematica/" rel="nofollow">Wolfram Mathematica</a> or highly optimized C codes using the SymPy-based <a data-is-external-link="true" href="http://nrpyplus.net/" rel="nofollow">NRPy+</a>.</p>
<p>Available from: <a data-is-external-link="true" href="https://nbviewer.jupyter.org/github/zachetienne/nrpytutorial/blob/master/NRPyPN/NRPyPN.ipynb" rel="nofollow">https://nbviewer.jupyter.org/github/zachetienne/nrpytutorial/blob/master/NRPyPN/NRPyPN.ipynb</a></p>
<p>--<br/>
Ticket URL: <a href='https://bitbucket.org/einsteintoolkit/tickets/issues/2417/include-pn-expressions-for-initial-momenta'>https://bitbucket.org/einsteintoolkit/tickets/issues/2417/include-pn-expressions-for-initial-momenta</a></p>
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