Hellings-Downs curve deformed by ultralight vector dark matter

Understand

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.