Periastron Advance in Black-Hole Binaries

TL;DR

This paper precisely calculates the relativistic periastron advance in black-hole binaries using numerical relativity and compares it with analytic models, finding high accuracy especially with the effective-one-body approach.

Contribution

First precise numerical relativity calculation of periastron advance in black-hole binaries, validating and comparing multiple analytic approximation schemes.

Findings

Effective-one-body model is highly accurate.

Self-force theory predictions are surprisingly accurate.

Results inform universal models for gravitational-wave detection.

Abstract

The general relativistic (Mercury-type) periastron advance is calculated here for the first time with exquisite precision in full general relativity. We use accurate numerical relativity simulations of spinless black hole binaries with mass ratios 1/8 < m1/m2 < 1 and compare with the predictions of several analytic approximation schemes. We find the effective-one-body model to be remarkably accurate, and, surprisingly, so also the predictions of self-force theory [replacing m1/m2 --> m1m2/(m1+m2)^2]. Our results can inform a universal analytic model of the two-body dynamics, crucial for ongoing and future gravitational-wave searches.