Analytic Investigation of the Branch Cut of the Green Function in Schwarzschild Space-time

Abstract

The retarded Green function for linear field perturbations in Schwarzschild black hole space-time possesses a branch cut in the complex-frequency plane. This branch cut has remained largely unexplored: only asymptotic analyses either for small-frequency (yielding the known tail decay at late times of an initial perturbation of the black hole) or for large-frequency (quasinormal modes close to the branch cut in this regime have been linked to quantum properties of black holes) have been carried out in the literature. The regime along the cut inaccessible to these asymptotic analyses has so far remained essentially unreachable. We present a new method for the analytic calculation of the branch cut directly on the cut for general-spin fields in Schwarzschild space-time. This method is valid for any values of the frequency on the cut and so it provides analytic access to the whole branch cut for the first time. We calculate the modes along the cut and investigate their properties and connection with quasinormal modes. We also investigate the contribution from these branch cut modes to the self-force acting on a point particle on a Schwarzschild background space-time.

26 pages, 18 figures

References in corpus (7)

• LIGO: The Laser Interferometer Gravitational-Wave Observatory
• The physical interpretation of the spectrum of black hole quasinormal modes
• WKB analysis of the Regge-Wheeler equation down in the frequency plane
• Self-Force Calculations with Matched Expansions and Quasinormal Mode Sums
• Asymptotic Spectroscopy of Rotating Black Holes
• Caustic echoes from a Schwarzschild black hole
• Pade Approximants of the Green Function in Spherically Symmetric Spacetimes

Cited by in corpus (5)

• Transient Instability of Rapidly Rotating Black Holes
• Spectroscopy of Extremal (and Near-Extremal) Kerr Black Holes
• Spectral instability of black holes: relating the frequency domain to the time domain
• High-order tail in Kerr spacetime
• Wavefront twisting by rotating black holes: orbital angular momentum generation and phase coherent detection