Dark Photon Stars: Formation and Role as Dark Matter Substructure

Abstract

Any new vector boson with non-zero mass (a `dark photon' or `Proca boson') that is present during inflation is automatically produced at this time from vacuum fluctuations and can comprise all or a substantial fraction of the observed dark matter density, as shown by Graham, Mardon, and Rajendran. We demonstrate, utilising both analytic and numerical studies, that such a scenario implies an extremely rich dark matter substructure arising purely from the interplay of gravitational interactions and quantum effects. Due to a remarkable parametric coincidence between the size of the primordial density perturbations and the scale at which quantum pressure is relevant, a substantial fraction of the dark matter inevitably collapses into gravitationally bound solitons, which are fully quantum coherent objects. The central densities of these `dark photon star', or `Proca star', solitons are typically a factor $10^6$ larger than the local background dark matter density, and they have characteristic masses of $10^{-16}{M}_{\odot }(10^{-5}\mathrm{eV}/m{)}^{3/2}$, where $m$ is the mass of the vector. During and post soliton production a comparable fraction of the energy density is initially stored in, and subsequently radiated from, long-lived quasi-normal modes. Furthermore, the solitons are surrounded by characteristic `fuzzy' dark matter halos in which quantum wave-like properties are also enhanced relative to the usual virialized dark matter expectations. Lower density compact halos, with masses a factor of $\sim 10^5$ greater than the solitons, form at much larger scales. We argue that, at minimum, the solitons are likely to survive to the present day without being tidally disrupted. This rich substructure, which we anticipate also arises from other dark photon dark matter production mechanisms, opens up a wide range of new direct and indirect detection possibilities, as we discuss in a companion paper.

A supplementary animation can be found at this link: http://www.youtube.com/watch?v=u9EV4Z2G6o0

References in corpus (19)

• Ultralight scalars as cosmological dark matter
• Cosmic Structure as the Quantum Interference of a Coherent Dark Wave
• Understanding the Core-Halo Relation of Quantum Wave Dark Matter, $\psi$DM, from 3D Simulations
• Disruption of Dark Matter Substructure: Fact or Fiction?
• Quantum Radiation of Oscillons
• Dark Photon Dark Matter from a Network of Cosmic Strings
• The survival and disruption of CDM micro-haloes: implications for direct and indirect detection experiments
• Astrophysical Effects of Scalar Dark Matter Miniclusters
• Structure Formation and Exotic Compact Objects in a Dissipative Dark Sector
• Axion minicluster power spectrum and mass function
• On mini-halo encounters with stars
• Imprints of the Early Universe on Axion Dark Matter Substructure
• Polarized Vector Oscillons
• Destruction of axion miniclusters in the Galaxy
• Gravitational Focusing of Wave Dark Matter
• Formation of inflaton halos after inflation
• Binary Collisions of Dark Matter Blobs
• Tidal stripping of dark matter subhalos by baryons from analytical perspectives: disk shocking and encounters with stars
• Stochastic Properties of Ultralight Scalar Field Gradients

Cited by in corpus (41)

• Small-scale structure in vector dark matter
• The problem with Proca: ghost instabilities in self-interacting vector fields
• Gravitational production of dark photon dark matter with mass generated by the Higgs mechanism
• Dark Photon Dark Matter without Stueckelberg Mass
• The meso-inflationary QCD axion
• Challenges and Opportunities of Gravitational Wave Searches above 10 kHz
• Kinetic relaxation and Bose-star formation in multicomponent dark matter- I
• Constraints on Dark Matter from Dynamical Heating of Stars in Ultrafaint Dwarfs. Part 2: Substructure and the Primordial Power Spectrum
• Unequal-mass boson-star binaries: Initial data and merger dynamics
• Soliton Merger Rates and Enhanced Axion Dark Matter Decay
• The non-spherical ground state of Proca stars
• Dark photon dark matter from an oscillating dilaton
• Improved Mixed Dark Matter Halo Model for Ultralight Axions
• Kinetic relaxation and nucleation of Bose stars in self-interacting wave dark matter
• Post-inflationary axions: a minimal target for axion haloscopes
• Yang-Mills stars in Higgsed non-Abelian dark matter
• Cosmological Simulations of Two-Component Wave Dark Matter
• Photons from dark photon solitons via parametric resonance
• Imaging dark matter at the smallest scales with $z\approx 1$ lensed stars
• Detectable and defect-free dark photon dark matter
• Experimental targets for dark photon dark matter
• i-SPin: An integrator for multicomponent Schrödinger-Poisson systems with self-interactions
• Searching for blue in the dark
• Compact objects in and beyond the Standard Model from non-perturbative vacuum scalarization
• New Constraints on Dark Matter and Cosmic Neutrino Profiles through Gravity
• Unified view of scalar and vector dark matter solitons
• Gravitationally produced Dark Matter and primordial black holes
• Phenomenology of wavelike vector dark matter nonminimally coupled to gravity
• Listening for Dark Photon Radio from the Galactic Centre
• First Search for Ultralight Dark Matter Using a Magnetically Levitated Particle
• Bracketing the soliton-halo relation of ultralight dark matter
• i-SPin 2: An integrator for general spin-s Gross-Pitaevskii systems
• Dark Spin-2 Field Solitons as a Source of Electromagnetic Radiation
• Early Growth of Structure in Warm Wave Dark Matter
• Diffuse X-Ray and Gamma-Ray Limits on Boson Stars that Interact with Nuclei
• Detecting gravitational signatures of dark matter with atom gradiometers
• Dark photon dark matter from flattened axion potentials
• Nonrelativistic Proca stars: Spherical stationary and multi-frequency states
• Scaling relations, dynamical heating and tidal disruption in spin $s$ ultralight dark matter models
• Linear stability of nonrelativistic Proca stars
• Probing Bosonic Overdensities with Optomechanical Sensing