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RESEARCH PRODUCT
Dark Photon Oscillations in Our Inhomogeneous Universe
Joshua T. RudermanHongwan LiuHongwan LiuSiddharth Mishra-sharmaAndrea Caputosubject
PhysicsFree electron modelCosmology and Nongalactic Astrophysics (astro-ph.CO)PhotonCosmic microwave backgroundDark matterFOS: Physical sciencesGeneral Physics and AstronomyPhysics::OpticsObservablePlasmaAstrophysics::Cosmology and Extragalactic Astrophysics01 natural sciencesDark photonCosmologyHigh Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)Quantum electrodynamics0103 physical sciences010306 general physicsAstrophysics - Cosmology and Nongalactic Astrophysicsdescription
A dark photon may kinetically mix with the ordinary photon, inducing oscillations with observable imprints on cosmology. Oscillations are resonantly enhanced if the dark photon mass equals the ordinary photon plasma mass, which tracks the free electron number density. Previous studies have assumed a homogeneous Universe; in this Letter, we introduce for the first time an analytic formalism for treating resonant oscillations in the presence of inhomogeneities of the photon plasma mass. We apply our formalism to determine constraints from Cosmic Microwave Background photons oscillating into dark photons, and from heating of the primordial plasma due to dark photon dark matter converting into low-energy photons. Including the effect of inhomogeneities demonstrates that prior homogeneous constraints are not conservative, and simultaneously extends current experimental limits into a vast new parameter space.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2020-02-12 |