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Hello all,
<br/>
<br/>here is a new thorn:
<a target="_blank" href="https://bitbucket.org/mjasiulek/llamawavehyperboloidal">https://bitbucket.org/mjasiulek/llamawavehyperboloidal</a>
<br/>
<br/>===============================================================================
<br/>LlamaWaveHyperboloidal
<br/>===============================================================================
<br/>
<br/>This thorn allows to evolve the scalar wave equation in 3D in Kerr spacetimes
<br/>using Kerr-Schild coordinates which are horizon penetrating. At some transition
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radius the user can specify where the Kerr-Schild slicing becomes hyperboloidal,
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thus, 'bends up' to scri (future null infinity). Therefore, no outer (and inner) boundary
<br/>conditions have to be set, radiation leaves the spacetime 'naturally' through
<br/>the inner horizon and scri. The waveform at scri is readily computed during the
<br/>evolution.
<br/>
<br/>It uses Llama's spherical 6-patch coordinates (r,u,v), the method-of-lines with
<br/>4th-order Runge-Kutta and 4th-,6th- or 8th-order spatial finite-differencing
<br/>and matching Kreiss-Oliger dissipation.
<br/>
<br/>In
<a target="_blank" href="http://arxiv.org/abs/1109.2513">http://arxiv.org/abs/1109.2513</a> (or
<a target="_blank" href="http://iopscience.iop.org/0264-9381/29/1/015008/">http://iopscience.iop.org/0264-9381/29/1/015008/</a>)
<br/>I used this code to study QNMs, late-time tails in Kerr at scri and to test the
<br/>novel hyperboloidal transformation used to smoothly attach the hyperboloidal
<br/>slice.
<br/>
<br/>If you find this code useful, please cite the paper Class. Quantum Grav. 29
<br/>015008 (2012).
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<br/>
<br/>
<br/>Enjoy,
<br/>Michael Jasiulek
<br/>
<br/>
<br/>.
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