Since 2002 Perimeter Institute has been recording seminars, conference talks, and public outreach events using video cameras installed in our lecture theatres. Perimeter now has 7 formal presentation spaces for its many scientific conferences, seminars, workshops and educational outreach activities, all with advanced audio-visual technical capabilities. Recordings of events in these areas are all available On-Demand from this Video Library and on Perimeter Institute Recorded Seminar Archive (PIRSA). PIRSA is a permanent, free, searchable, and citable archive of recorded seminars from relevant bodies in physics. This resource has been partially modelled after Cornell University's arXiv.org.
Black hole-neutron star binary (BHNS) mergers are likely sources for detectable gravitational radiation and candidate engines for short-hard gamma-ray bursts. However, accurate modeling of these mergers requires fully general relativistic simulations, incorporating both relativistic hydrodynamics for the matter and Einstein's field equations for the (strong) gravitational fields. I will review techniques and results from recent fully general relativistic BHNS merger simulations.
The familiar post-Newtonian inspiral description of a binary neutron star system is sufficient for detection in current instruments. However, as we consider making astrophysical measurements using advanced detectors, the effects of matter and strong gravity on gravitational wave signals may become significant. I will review recent work modelling the waveforms produced by the inspiral and coalescence of binary neutron stars. In the mid-to-late inspiral this includes modifications to the post-Newtonian waveform models from tidal deformations.
A coherent multi-site search is expected to be more powerful than itscoincident counterpart in discriminating gravitational wave (GW) signals fromthe noise background. This is because the former tests the consistency of thesignals' amplitudes phases and time-delays across the sites with those expected from a real GW source. However the coherent statistic that is optimalin Gaussian noise is not guaranteed to perform as well in real data which arenon-Gaussian.
In this talk we present the motivation behind our implementation of and results from a coherent search for spinning compact binary coalescences. Our method uses the Physical template family of waveforms which describe binaries where only one of the objects has spin. In addition we discuss the possibility of extending thissearch to incorporate template waveforms for precessing black hole mergers derived from numerical relativity.
We present simulations of non-spinning unequal mass black-hole binaries with mass ratio q=1/4 covering approximately 11 orbits prior to coalescence and merger obtained with the moving puncture technique. Accuracy of the simulations and matching to post-Newtonian waveforms is discussed.
In this talk I will show recent results obtained by the RIT group fromsimulations of highly-spinning binaries including new data that givesnear maximal spins and high-mass ratio binaries. Simulations in bothof these regimes are numerically challenging. However asastrophysical binaries are expected to be highly-spinning and havehigh mass ratios accurate simulations in these regimes are crucialfor understanding the dynamics of realistic binaries.
©2012 Institut Périmètre de Physique Théorique