The second data release from the European Pulsar Timing Array: VI. Challenging the ultralight dark matter paradigm

TL;DR

This study uses the European Pulsar Timing Array's second data release to test ultralight dark matter models, finding strong constraints on particle mass and local density, challenging the idea that such particles make up all dark matter.

Contribution

It provides the first robust constraints on ultralight dark matter particle mass and density using pulsar timing data from the latest European Pulsar Timing Array release.

Findings

Ultralight particles with masses between 10^{-24} and 10^{-23.3} eV cannot be all of the local dark matter.

The maximum local density of such particles is constrained to be less than approximately 0.3 GeV/cm^3.

The results challenge the ultralight dark matter paradigm as the sole component of dark matter.

Abstract

Pulsar Timing Array experiments probe the presence of possible scalar or pseudoscalar ultralight dark matter particles through decade-long timing of an ensemble of galactic millisecond radio pulsars. With the second data release of the European Pulsar Timing Array, we focus on the most robust scenario, in which dark matter interacts only gravitationally with ordinary baryonic matter. Our results show that ultralight particles with masses $10^{-24.0}~\text{eV} \lesssim m \lesssim 10^{-23.3}~\text{eV}$ cannot constitute $100\%$ of the measured local dark matter density, but can have at most local density $\rho\lesssim 0.3$ GeV/cm$^3$.