Constraints on the Nieh-Yan modified teleparallel gravity with gravitational waves

TL;DR

This paper investigates the effects of the Nieh-Yan parity-violating term on gravitational wave propagation, deriving waveform modifications, and constrains the theory using LIGO/Virgo data, finding no significant parity violation.

Contribution

It provides the first observational constraints on the Nieh-Yan modified teleparallel gravity through gravitational wave analysis.

Findings

No significant evidence of parity violation detected.

Placed an upper bound on the energy scale $M_{PV} < 6.5 imes 10^{-42}$ GeV.

Derived phase modifications in GW waveforms due to parity violation.

Abstract

The discovery of gravitational waves (GWs) from the compact binary components by LIGO/Virgo Collaboration provides an unprecedented opportunity for testing gravity in the strong and highly dynamical field regime of gravity. Currently a lot of model-independent tests have been performed by LIGO/Virgo Collaboration and no any significant derivation from general relativity has been found. In this paper, we study the parity violating effects on the propagation of GWs in the Nieh-Yan modified teleparallel gravity, a theory which modifies general relativity by a parity violating Nieh-Yan term. We calculate the corresponding parity violating waveform of GWs produced by the coalescence of compact binaries. By comparing the two circular polarization modes, we find the effects of the velocity birefringence of GWs in their propagation caused by the parity violation due to the Nieh-Yan term, which are explicitly presented in the GW waveforms by the phase modification. With such phase modifications to the waveform, we perform the full Bayesian inference with the help of the open source software {\texttt Bilby} on the GW events of binary black hole merges (BBH) in the LIGO-Virgo catalogs GWTC-1 and GWTC-2. We do not find any significant evidence of parity violation due to the parity violating Nieh-Yan term and thus place an upper bound on the energy scale $M_{\rm PV} < 6.5 \times 10^{-42} \; {\rm GeV}$ at 90\% confidence level, which represents the first constraint on the Nieh-Yan modified teleparallel gravity so far.