Constraints on cosmological viscosity and self interacting dark matter from gravitational wave observations

TL;DR

This paper explores how gravitational wave observations can constrain the shear viscosity of dark matter and dark energy, showing that future detections could improve these constraints significantly.

Contribution

It introduces a method to constrain dark matter and dark energy viscosities using gravitational wave dissipation data from GW150914.

Findings

Gravitational waves dissipate energy in viscous media proportional to shear viscosity.

Current GW data can set upper bounds on dark matter and dark energy viscosities.

Future GW observations could tighten these constraints substantially.

Abstract

It has been shown that gravitational waves propagate through ideal fluids without experiencing any dispersion or dissipation. However, if the medium has a non-zero shear viscosity $\eta$ , gravitational waves will be dissipated at a rate proportional to $G \,\eta$. We constrain dark matter and dark energy models with non-zero shear viscosity by calculating the dissipation of gravitational waves from GW150914 which propagate over a distance of $410\, $ Mpc through the dissipative fluid and comparing the data with the theoretical prediction. This provides a proof-of-principle demonstration of the fact that future observations gravitational waves at LIGO have the potential of better constraining the viscosity of dark matter and dark energy.