Parity-breaking galaxy 4-point function from lensing by chiral gravitational waves
Abstract
Recent searches for parity breaking in the galaxy four-point correlation function, as well as the prospects for greatly improved sensitivity to parity breaking in forthcoming surveys, motivate the search for physical mechanisms that could produce such a signal. Here we show that a parity-violating galaxy four-point correlation function may be induced by lensing by a chiral gravitational-wave background. We estimate the amplitude of a signal that would be detectable with a current galaxy survey, taking into account constraints to the primordial gravitational-wave-background amplitude. We find that this mechanism is unlikely to produce a signal large enough to be seen with a galaxy survey but note that it may come within reach with future 21cm observations.
Cite
@article{arxiv.2408.03994,
title = {Parity-breaking galaxy 4-point function from lensing by chiral gravitational waves},
author = {Keisuke Inomata and Leah Jenks and Marc Kamionkowski},
journal= {arXiv preprint arXiv:2408.03994},
year = {2025}
}
Comments
10 pages, 2 figures, v2: minor changes, version published in PRD