Scalar induced gravitational waves in symmetric teleparallel gravity with a parity-violating term

TL;DR

This paper studies scalar induced gravitational waves within symmetric teleparallel gravity incorporating a parity-violating term, revealing negligible effects from parity violation but significant contributions from connection perturbations, leading to distinctive multipeak signatures.

Contribution

It introduces the analysis of SIGWs in symmetric teleparallel gravity with parity violation, highlighting the importance of connection perturbations for observable signatures.

Findings

Parity-violating term causes velocity birefringence in SIGWs

Connection perturbations produce a multipeak structure in SIGW energy density

Parity violation effects are negligible under current GW speed constraints

Abstract

Gravitational waves (GWs) are useful to test gravitational theories and to probe the physics in the early universe. In this paper, we investigate the scalar induced gravitational waves (SIGWs) in symmetric teleparallel gravity with a parity-violating term. The presence of the parity-violating term leads to the velocity birefringence effect of the SIGWs. However, after taking into account the observational constraints on the speed of GWs, the contribution from the parity-violating term to SIGWs is negligible. Nevertheless, the contribution to SIGWs from the perturbations of the connection can be significant, and results in a multipeak structure in the energy density of SIGWs. This feature makes the symmetric teleparallel gravity distinguishable from the general relativity.