Prospects of Probing Dark Matter Condensates with Gravitational Waves

TL;DR

This paper investigates how gravitational wave speed measurements can constrain various dark matter condensate models, finding that current detectors are ineffective but future radio telescopes could test fuzzy dark matter.

Contribution

It introduces a novel method to constrain dark matter condensate models using gravitational wave speed data and assesses the potential of future radio telescopes for these tests.

Findings

Current GW detectors cannot constrain the models.

Detection frequencies below 10^{-9} Hz could provide meaningful constraints.

Fuzzy dark matter is the most promising model for future validation.

Abstract

The Lambda-Cold Dark Matter model explains cosmological observations most accurately till date. However, it is still plagued with various shortcomings at galactic scales. Models of dark matter such as superfluid dark matter, Bose-Einstein Condensate(BEC) dark matter and fuzzy dark matter have been proposed to overcome some of these drawbacks. In this work, we probe these models using the current constraint on the gravitational wave (GW) propagation speed coming from the binary neutron star GW170817 detection by LIGO-Virgo detector network and use it to study the allowed parameter space for these three models for Advanced LIGO+Virgo, LISA, IPTA and SKA detection frequencies. The speed of GW has been shown to depend upon the refractive index of the medium, which in turn, depends on the dark matter model parameters through the density profile of the galactic halo. We constrain the parameter space for these models using the bounds coming from GW speed measurement and the Milky Way radius bound. Our findings suggest that with Advanced LIGO-Virgo detector sensitivity, the three models considered here remain unconstrained. A meaningful constraint can only be obtained for detection frequencies $\leq 10^{-9}$ Hz, which falls in the detection range of radio telescopes such as IPTA and SKA. Considering this best possible case, we find that out of the three condensate models, the fuzzy dark matter model is the most feasible scenario to be falsified/ validated in near future.