Simulations of Shapiro, Gravitational, and Doppler time delays in pulsar networks for ultralight dark matter

TL;DR

This paper simulates pulsar signals affected by ultralight dark matter-induced metric perturbations, estimating time delays and comparing analytical and simulated results to assess observational detectability.

Contribution

It introduces a simulation framework for pulsar timing affected by ultralight dark matter fluctuations and compares these with analytical estimates and observational sensitivities.

Findings

Simulated pulsar signals show measurable time delays due to ultralight dark matter.

Analytical estimates align well with simulation results.

Current pulsar observations may have sensitivity to detect these effects.

Abstract

The study of ultralight dark matter helps to constrain the lower bound of the mass in minimally coupled dark matter models. The granular structure of ultralight dark matter density fields produces metric perturbations which have been identified as a potentially interesting probe of this model. For dark matter masses $m \gtrsim 10^{-17} \, \mathrm{eV}$, these perturbations would fluctuate on timescales comparable to observational timescales. In this paper, we estimate the expected time delay these fluctuations would generate in simulated pulsar signals. We simulate arrays of mock pulsars in a fluctuating granular density field. We calculate the expected Shapiro time delay, gravitational redshift, and Doppler shift and compare analytical estimates with the results of simulations. Finally, we provide a comparison with existing pulsar observation sensitivities.