Pulsar Timing Residual induced by Wideband Ultralight Dark Matter with Spin 0, 1, 2

TL;DR

This paper explores how ultralight dark matter with different spins can produce wideband signals in pulsar timing residuals, potentially explaining the stochastic background observed by NANOGrav.

Contribution

It introduces a multifield ultralight dark matter model that generates a broad spectrum of pulsar timing signals and performs Bayesian analysis to constrain its parameters.

Findings

Ultralight dark matter can produce a wide spectrum of pulsar timing signals.

The stochastic background detected by NANOGrav may be explained by ultralight dark matter.

Bayesian analysis constrains ultralight dark matter parameters.

Abstract

The coherent oscillation of ultralight dark matter in the mass regime around $10^{-23}$ eV induces changes in gravitational potential with the frequency in the nanohertz range. This effect is known to produce a monochromatic signal in the pulsar timing residuals. Here we discuss a multifield scenario that produces a wide spectrum of frequencies, such that the ultralight particle oscillation can mimic the pulsar timing signal of stochastic common spectrum process. We discuss how ultralight dark matter with various spins produces such a wide band spectrum on pulsar timing residuals and perform the Bayesian analysis to constrain the parameters. It turns out that the stochastic background detected by NANOGrav can be associated with a wideband ultralight dark matter.