Constraining the EdGB theory with higher harmonics and merger-ringdown contribution using GWTC-3

TL;DR

This paper refines tests of Einstein-dilation-Gauss-Bonnet gravity using gravitational wave data, incorporating higher harmonics and merger-ringdown phases, resulting in tighter constraints on the theory's parameters.

Contribution

It introduces a more comprehensive analysis of GW data by including higher harmonics and merger-ringdown contributions, improving bounds on EdGB gravity parameters.

Findings

Best constraint: $\

rom GW200115, ound or rom urther or rom merger-ringdown data.

Abstract

In this paper, we revisit the problem of using gravitational wave data to test the Einstein-dilation-Gauss-Bonnet theory, by using nine selected gravitational wave events from GWTC-3. Compared with existing work, we are taking into account the higher harmonics more properly and we also study the contribution of the merger-ringdown data. Using the inspiral data alone, we find that the best result is from GW200115, giving $\sqrt{|\alpha|} < 1.1$ km, which is about 17\% tighter than the previous best result. We also notice the possible existence of a simple unexpected relation among the constraints from different events. Several combinations of the selected events give $\sqrt{|\alpha|} \leq 1.0$ km. The result is further improved when the merger-ringdown data is also included, using two phenomenological schemes, giving $\sqrt{|\alpha|} < 0.87$ km for GW200115 in the best case scenario.