6533b7d9fe1ef96bd126cf36
RESEARCH PRODUCT
Ultralight dark photon as a model for early universe dark matter
I. B. SamsonovVictor V. FlambaumVictor V. Flambaumsubject
PhysicsParticle physicsCold dark matterCosmology and Nongalactic Astrophysics (astro-ph.CO)010308 nuclear & particles physicsEquation of state (cosmology)Dark matterOrder (ring theory)FOS: Physical sciencesAstrophysics::Cosmology and Extragalactic AstrophysicsCoupling (probability)01 natural sciencesDark photonsymbols.namesakeHigh Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)0103 physical sciencessymbolsBaryon acoustic oscillations010306 general physicsHubble's lawAstrophysics - Cosmology and Nongalactic Astrophysicsdescription
Dark photon is a massive vector field which interacts only with the physical photon through the kinetic mixing. This coupling is assumed to be weak so that the dark photon becomes almost unobservable in processes with elementary particles, but can serve as a dark matter particle. We argue that in very early Universe ($z>3000$) this vector field may have the equation of state of radiation ($w=1/3$) but later behaves as cold dark matter ($w=0$). This may slightly change the expansion rate of the Universe at early time and reduce the value of the sound horizon of baryon acoustic oscillations (standard ruler). As a result, in this model the value of the Hubble constant appears to be larger than that in the standard $\Lambda$CDM model. In particular, it is sufficient to have the dark photon mass of order $m\sim 10^{-27}-10^{-25}$ eV to fit the value of the Hubble constant to $H_0 = 73$ km$\cdot$s$^{-1}$Mpc$^{-1}$ thus resolving the Hubble tension.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2019-08-25 |