Constraining ultralight vector dark matter with the Parkes Pulsar Timing Array second data release

Composed of ultralight bosons, fuzzy dark matter provides an intriguing solution to challenges that the standard cold model encounters on sub-galactic scales. The with mass $m\sim10^{-23} \rm{eV}$ will induce a periodic oscillation in gravitational potentials frequency nanohertz band, leading observable effects arrival times radio pulses from pulsars. Unlike scalar matter, pulsar timing signals induced by vector are dependent direction fields. In this work, we search for range $[2\times 10^{-24}, 2\times 10^{-22}]{\rm{eV}}$ through its effect Parkes Pulsar Timing Array (PPTA) second data release. Since no statistically significant detection is made, place $95\%$ upper limits local density as $\rho_{\rm{\tiny{VF}}} \lesssim 5{\rm{GeV/cm^{3}}}$ $m\lesssim 10^{-23}{\rm{eV}}$. As preferred found these constraints comparable those given earlier 12-year set PPTA.