Constraining the topological Gauss-Bonnet coupling from GW150914

TL;DR

This paper uses gravitational wave data from GW150914 to set the first observational constraints on the topological Gauss-Bonnet coupling in four-dimensional gravity, linking black hole mergers to fundamental physics.

Contribution

It provides the first observational bound on the 4D topological Gauss-Bonnet coupling using gravitational wave data and black hole area theorems.

Findings

Bound on Gauss-Bonnet coupling: $oxed{ ext{approximately } 2.8 imes 10^{9} ext{ m}^2}$

Supports the validity of the second law in black hole mergers

Links gravitational wave observations to fundamental topological parameters.

Abstract

Recent gravitational wave observation based on the data from GW150914 has confirmed Hawking's area theorem and estimated the increase in total horizon area during a merger process of two Kerr black holes. We use this result and the validity of the second law to obtain the first observational bound on the 4D topological Gauss-Bonnet coupling as $\gamma \lesssim 2.804^{+7.946}_{-1.169} \times 10^{9}\, m^2$ with $95 \%$ credibility.