Description
Ultralight bosons are well-motivated dark-matter candidates that can behave as coherent oscillating fields on Galactic scales. At the lower end of the mass spectrum, these oscillations can remain coherent for decades and leave detectable signatures in high-precision astrophysical observations. Binary pulsars are particularly powerful probes of such effects.
We investigate quadratically coupled scalar dark matter and spin-1 vector dark matter. We show how these fields perturb binary orbits, inducing variations in pulse arrival times, and use a Bayesian framework to combine information from different systems while accounting for orbital uncertainties. For scalar dark matter, we probe masses between $2\times10^{-22}$ and $2\times10^{-21} \, \, \mathrm{eV}$, a region inaccessible to other current searches. For vector dark matter, our sensitivity estimates are competitive with laboratory and space-based experiments near orbital resonances. These results highlight binary pulsar timing as a complementary probe of ultralight dark matter.