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Department of Physics and Astronomy
Seminars/Colloquia, Spring 2010

Unless noted otherwise, Tuesday Colloquia are at 4:00 pm
with refreshments served 15 minutes before each colloquium.

Scheduling for additional seminars will vary.

Abstracts of Talks

Steve Drasco Astrophysical Relativity Albert Einstein Institute Potsdam-Golm (Germany) Observing Black-Hole Binaries with Non-Trival Mass Ratios Pairs of black holes inspiraling toward each other are probably the most eagerly sought and well studied sources of gravitational waves. Currently, gravitational-wave observers are confining their searches to systems with relatively simple motion, and in which the ratio of the two black hole masses is rather close to 1. I will explain what we can expect from future observations that will broaden the current searches to include systems with mass ratios that are far from 1, and with motion that is wildly different from familiar Keplerian ellipses.

Yi Pan Department of Physics University of Maryland Analytical Modeling of Binary Black Hole Coalescence: Dynamics and Gravitational-wave Radiation Coalescing binary black holes are among the most promising sources for laser interferometric gravitational-wave detectors. The accurate analytical modeling of their dynamics and gravitational-wave radiation is essential for the detection of black-hole binaries and the extraction of source parameters. I will present waveforms of gravitational-wave radiation from coalescing binary black holes generated within the analytical effective-one-body approach. These waveforms agree, within numerical errors, with non-precessing waveforms generated by highly accurate numerical relativity simulations. I will show how this analytical approach extracts non-perturbative information contained in the numerical simulations, models the full coalescence phase, and provides a sufficiently accurate bank of waveforms to be used in matched-filtering based searches of coalescing binary black holes with gravitational-wave detectors.

Enrico Barausse Department of Physics University of Maryland Hamiltonian of a Spinning Test-Particle in Curved Spacetime We compute the unconstrained Hamiltonian of a spinning test-particle in a curved spacetime at linear order in the particle's spin. The equations of motion of this unconstrained Hamiltonian coincide with the Mathisson-Papapetrou-Pirani equations. We then use the formalism of Dirac brackets to derive the constrained Hamiltonian and the corresponding phase-space algebra in the Newton-Wigner spin supplementary condition, suitably generalized to curved spacetime, and find that the phase-space algebra (q,p,S) is canonical at linear order in the particle spin. We provide explicit expressions for this Hamiltonian in static spherically symmetric spacetimes, as well as in stationary axis-symmetric ones, and show how these could be useful to build a novel effective-one-body model for spinning black-hole binaries.