Hellings-Downs curve deformed by ultralight vector dark matter

TL;DR

This paper investigates how ultralight vector dark matter can deform the Hellings-Downs curve in pulsar timing arrays, potentially affecting gravitational wave detection and providing a new way to probe dark matter properties.

Contribution

It demonstrates that ultralight vector dark matter can deform the Hellings-Downs correlation curve, revealing a novel interaction between dark matter and gravitational wave detection methods.

Findings

Ultralight vector dark matter deforms the Hellings-Downs curve.

Deformation of the correlation curve can indicate the presence of dark matter with spin.

Potential impact on gravitational wave detection accuracy.

Abstract

Pulsar timing arrays (PTAs) provide a way to detect gravitational waves (GWs) at nanohertz frequencies. To ensure the detection of GWs, observational data must exhibit the Hellings-Downs angular correlation. It is also known that PTAs can probe ultralight dark matter. In this paper, we consider possible contamination of the Hellings-Downs angular correlation by the ultralight dark matter. We find that ultralight vector dark matter can give rise to the deformation of the Hellings-Downs correlation curve. Thus, the Hellings-Downs correlation curve could contain information on ultralight dark matter with a spin.