Signatures of asymmetry: Gravitational wave memory and the parity violation

TL;DR

This paper discusses how gravitational wave memory could reveal parity violation in gravity, with implications for fundamental physics, by using next-generation detectors to detect amplified cosmological signatures.

Contribution

It introduces the concept of integrated cosmological memory (ICM) as a novel method to detect and amplify parity-violating effects in gravitational waves over cosmological distances.

Findings

ICM can significantly amplify parity-violating signatures in GWs.

Next-generation GW detectors can probe fundamental symmetries.

Potential to constrain gravity parameters and explore particle physics-cosmology connections.

Abstract

Einstein's equivalence principle suggests a deep connection between matter and spacetime, prompting the question: if matter violates parity, must gravity? This letter explores the detection of parity violation in gravity using gravitational wave (GW) memory. Gravitational parity violation could be observable through GW amplitude birefringence and large-scale structure correlations. With improved sensitivity, next-generation GW detectors offer unprecedented opportunities to probe these effects. We propose that the integrated cosmological memory (ICM) of GWs, amplified over cosmological distances, can enhance faint parity-violating signatures. Specifically, if GWs from astrophysical events have differing polarization amplitudes, as in Chern-Simons gravity, ICM significantly amplifies this disparity. ICM uniquely and independently allows us to test fundamental symmetries, constrain gravity parameters, and gain insights into the interplay of particle physics, cosmology and gravity.