Accretion, Evaporation and Superradiance Phase Diagram of (Primordial) Black Holes and $10^{-21}-10^{21}$ eV Scalar, Vector, Tensor Fields

Caner Unal

Accretion, Evaporation and Superradiance Phase Diagram of (Primordial) Black Holes and $10^{-21}-10^{21}$ eV Scalar, Vector, Tensor Fields

Caner Unal

Abstract

We obtain the accretion, evaporation and superradiance phase diagram of astrophysical and primordial black holes in the mass range $10^{-33}-10^{11} \, M_\odot $. This black hole mass range corresponds to production of $10^{-21} - 10^{21}$ eV particles for superradiance (bosons) and evaporation (bosons and fermions). Only accretion and superradiance processes are relevant for heavy black holes, on the other hand for light black holes of primordial origin, all three processes can be relevant. We find that superradiance instability can happen even for black hole spin values as low as $10^{-9}-10^{-2}$. Since light black holes are very unstable to these perturbations and sensitive probes of bosonic particles, a single moderately spinning BH can probe 2-9 orders of magnitude of mass parameter space depending on the nature of the perturbations that are scalar (axion), vector (dark photon and/or photon with effective mass) and spin-2. If spinning black holes are observed and superradiance is not observed, possibly due to self-interactions, we find limits on the axion/scalar decay constant and energy density. We generalize these bounds for vector and spin-2 fields.

Accretion, Evaporation and Superradiance Phase Diagram of (Primordial) Black Holes and $10^{-21}-10^{21}$ eV Scalar, Vector, Tensor Fields

Abstract

We obtain the accretion, evaporation and superradiance phase diagram of astrophysical and primordial black holes in the mass range

. This black hole mass range corresponds to production of

eV particles for superradiance (bosons) and evaporation (bosons and fermions). Only accretion and superradiance processes are relevant for heavy black holes, on the other hand for light black holes of primordial origin, all three processes can be relevant. We find that superradiance instability can happen even for black hole spin values as low as

. Since light black holes are very unstable to these perturbations and sensitive probes of bosonic particles, a single moderately spinning BH can probe 2-9 orders of magnitude of mass parameter space depending on the nature of the perturbations that are scalar (axion), vector (dark photon and/or photon with effective mass) and spin-2. If spinning black holes are observed and superradiance is not observed, possibly due to self-interactions, we find limits on the axion/scalar decay constant and energy density. We generalize these bounds for vector and spin-2 fields.

Paper Structure (28 equations, 6 figures)

This paper contains 28 equations, 6 figures.

Figures (6)

Figure 1: The minimum spin required for the black holes in the $10^{-33}-10^{11}\, M_\odot$ mass range to experience superradiance
Figure 2: Phase Diagram of Black Holes for (Eddington) accretion, evaporation, (scalar, vector and tensor) superradiance
Figure 3: Scalar, Vector and Spin-2 (Tensor) particles probed by superradiance of light (less than solar mass) BHs
Figure 4: Top: Bounds on ${\rm f_{axion}}$ in the presence of spinning light BHs as a function of scalar/axion mass; Bottom: Bounds on the energy density as a function of scalar/axion mass
Figure 5: Top: Bounds on ${\rm f_{vector}}$ in the presence of spinning light BHs as a function of vector mass; Bottom: Bounds on the energy density as a function of vector mass
...and 1 more figures