Abstract
We study the ultralight vector dark matter with a mass around 10^{-23},mathrm {eV}. The vector field oscillating coherently on galactic scales induces oscillations of the spacetime metric with a frequency around nHz, which is detectable by pulsar timing arrays. We find that the pulsar timing signal due to the vector dark matter has nontrivial angular dependence unlike the scalar dark matter and the maximal amplitude is three times larger than that of the scalar dark matter.
Highlights
Observations of the galactic rotation curves [1], structure formation [2], and gravitational lensing [3] suggest that the invisible matter, the so-called dark matter (DM) exists in the Universe
We have studied the pulsar timing signal of the ultralight vector DM
The vector DM in a galactic halo oscillates coherently and monochromatically with a specific frequency determined by its mass (24)
Summary
Observations of the galactic rotation curves [1], structure formation [2], and gravitational lensing [3] suggest that the invisible matter, the so-called dark matter (DM) exists in the Universe. The approaches to search for the vector DM or to constrain its couplings to particles in the Standard Model have been proposed, e.g. by using ground-based gravitational-wave interferometers [13,14] or taking into account the cosmological plasma effects with a photon [15]. A coherently oscillating vector field behaves as a non-relativistic pressureless matter on cosmological scales It does not induce the anisotropic expansion of the Universe [25]. The detection method is applicable to the case of the vector DM and it is expected that a specific signal depending on the vector property appears. This is what we will discuss in this paper. Appendix A is devoted to derivation of the formula for the redshift of photons induced by metric perturbations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
