TOPICAL REVIEW: Gravitational selfforce in extreme massratio inspirals
Abstract
This review is concerned with the gravitational selfforce acting on a mass particle in orbit around a large black hole. Renewed interest in this old problem is driven by the prospects of detecting gravitational waves from strongly gravitating binaries with extreme mass ratios. We begin here with a summary of recent advances in the theory of gravitational selfinteraction in curved spacetime, and proceed to survey some of the ideas and computational strategies devised for implementing this theory in the case of a particle orbiting a Kerr black hole. We review in detail two of these methods: (i) the standard modesum method, in which the metric perturbation is regularized modebymode in a multipole decomposition, and (ii) mmode regularization, whereby individual azimuthal modes of the metric perturbation are regularized in 2+1 dimensions. We discuss several practical issues that arise, including the choice of gauge, the numerical representation of the particle singularity, and how highfrequency contributions near the particle are dealt with in frequencydomain calculations. As an example of a full endtoend implementation of the modesum method, we discuss the computation of the gravitational selfforce for eccentric geodesic orbits in Schwarzschild, using a direct integration of the Lorenzgauge perturbation equations in the time domain. With the computational framework now in place, researchers have recently turned to explore the physical consequences of the gravitational selfforce; we will describe some preliminary results in this area. An appendix to this review presents, for the first time, a detailed derivation of the 'regularization parameters' necessary for implementing the modesum method in Kerr spacetime.
 Publication:

Classical and Quantum Gravity
 Pub Date:
 November 2009
 DOI:
 10.1088/02649381/26/21/213001
 arXiv:
 arXiv:0908.1664
 Bibcode:
 2009CQGra..26u3001B
 Keywords:

 General Relativity and Quantum Cosmology;
 Astrophysics  High Energy Astrophysical Phenomena
 EPrint:
 Invited topical review for CQG