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.
In this work we investigate the electromagnetic radiation induced by a binary black hole merger when they are surrounded by a force-free environment (i.e. plasma with inertia terms negligible compared to the electromagnetic stresses). We discuss the relevance of this system for possible multimessenger astronomy with binary black holes.
I will report on some recent results obtained using the fully general relativistic magnetohydrodynamic code Whisky in simulating equal and unequal-mass binary neutron star (BNS) systems during the last phases of inspiral, merger and collapse to black hole surrounded by a torus. BNSs are among the most important sources of gravitational waves which are expected to be detected by the current or next generation of gravitational wave detectors, such as LIGO and Virgo, and they are also thought to be at the origin of very important astrophysical phenomena, such as short gamma-ray bursts.
We describe a Markov-Chain Monte-Carlo technique to study the source parameters of gravitational-wave signals from the inspirals of stellar-mass compact binaries detected with ground-based detectors such as LIGO and Virgo. We can apply this technique to both spinning and non-spinning waveforms and we use a variety of tools like parallel tempering to improve the sampling efficiency of the algorithm in a multi-dimensional parameter space. We describe new developments in model-selection techniques for distinguishing between alternative signal models.
Direct detection of gravitational wave stands at a cross roads; the first generation of interferometric detectors will soon be decommissioned and the second generation projects are underway. In this talk, I will describe the Initial LIGO and VIRGO generation of instruments, the techniques required to achieve a strain sensitivity of 3 x 10^{-23} and an NS / NS inspiral range of 15 Mpc. I'll follow with a description of the Advanced detectors and the differences that should improve the sensitivity by a factor of ten.
We present a new construction of phenomenological templates for non-precessing spinning black hole binaries. This approach utilizes a frequency domain matching of post-Newtonian inspiral waveforms with numerical relativity based binary black hole coalescence waveforms. We quantify the various possible sources of systematic errors that could arise in matching post-Newtonian and numerical relativity waveforms and we use a matching criteria based on minimizing these errors.
I will review recent advances in the effective-one-body formalism aimed at describing the dynamics and gravitational-wave emission from coalescing black holes. I will discuss the implications of those advances for the search of gravitational waves from binary black holes and for the recoil velocity of black holes formed through merger.
The dynamics of black-hole binaries is a very complex problem which has been solved only very recently through time-expensive numerical-relativity calculations. In spite of this mathematical complexity many results of these calculations can be accurately reproduced with phenomenological approaches based on test particles combined with Post-Newtonian theory and black-hole perturbation theory. In this talk I will focus on effective-one-body models, which have proved a useful and fast tool to accurately reproduce numerical-relativity waveforms.
The quest for gravitational waves from binary inspiral is performed via matched filtering and thus requires a detailed knowledge of the signal. For non-precessing binaries complete analytic waveforms exist from inspiral to merger and ring-down. Here we present complete waveforms for generically spinning equal mass systems.They have been constructed by bridging the gap between the analytically known inspiral phase described by spin Taylor (T4) approximants in the restricted waveform approximation and the ring-down phase.
Recently generated asymptotic expansions zanolin et al. arXiv:0912.0065 [gr-qc] showa frequentist approach to go beyond Fisher information assessments of the accuracy for maximum likelihood parameter estimations. In this talk we describe the application of these techniques to directional reconstruction fornumerical relativity waveforms.
Most searches with ground-based detectors for gravitational-wave signals from the inspirals of stellar-mass compact binaries use template based methods. Those work well for non-spinning systems but since the dimensionality of the parameter space of spinning waveforms is large a template bank search is not feasible. We describe Bayesian and Markov-chain Monte-Carlo methods for parameter estimation of spinning waveforms using hybrid spinning waveforms matching the ringdown from Numerical Relativity results. We compare those results when using post-Newtonian only waveforms.