Constraining the mass of dark photons and axion-like particles through black-hole superradiance

Abstract

Ultralight bosons and axion-like particles appear naturally in different scenarios and could solve some long-standing puzzles. Their detection is challenging, and all direct methods hinge on unknown couplings to the Standard Model of particle physics. However, the universal coupling to gravity provides model-independent signatures for these fields. We explore here the superradiant instability of spinning black holes triggered in the presence of such fields. The instability taps angular momentum from and limits the maximum spin of astrophysical black holes. We compute, for the first time, the spectrum of the most unstable modes of a massive vector (Proca) field for generic black-hole spin and Proca mass. The observed stability of the inner disk of stellar-mass black holes can be used to derive direct constraints on the mass of dark photons in the mass range 10 −13 eV m V 3 × 10 −12 eV. By including also higher azimuthal modes, similar constraints apply to axion-like particles in the mass range 6 × 10 −13 eV m ALP 10 −11 eV. Likewise, mass and spin distributions of supermassive BHs -as measured through continuum fitting, Kα iron line, or with the future space-based gravitational-wave detector LISA -imply indirect bounds in the mass range approximately 10 −19 eV m V , m ALP 10 −13 eV, for both axion-like particles and dark photons. Overall, superradiance allows to explore a region of approximately 8 orders of magnitude in the mass of ultralight bosons.

Massive vector fields in Kerr-Newman and Kerr-Sen black hole spacetimes

“…The critical mass mM above which the instability ceases to exist decreases when J/M 2 decreases. These behaviours for the superradiant instability of massive Proca fields are similar to those found in massive scalars in the Kerr black hole, as pointed out in [10,31,33]. The plots in the lower panel of Fig.…”

“…Although direct detection of dark matter proves to be very difficult, recently a new line of investigation has opened up with a flurry of papers considering the interplay of these ultralight bosons and superradiance from black holes [7][8][9][10][11][12]. In particular, it has been shown that the instabilities from these superradiant modes can, in principle, be used to detect beyond Standard Model particles [7] and put bounds on the potential masses of dark matter candidates, e.g.…”

“…Even for vacuum (Kerr) black holes, the corresponding Proca equations are rather complicated partial differential equations whose direct decoupling and separation à la Teukolsky [22,23] does not work due to the presence of the mass term [24,25]. As a consequence the problem was investigated either using approximations [9,24,25] or employing serious numerical analysis [10,26,27].However, a separability renaissance for vector fields has begun in the last couple of years due to a new ansatz by Lunin [28]. Simplified and written in covariant form by Frolov-Krtouš-Kubizňák [29,30], the new ansatz works for the massive vector field case [31] and can be applied in the Kerr-NUT-AdS spacetimes for all dimensions.…”

Tidal effects and disruption in superradiant clouds: A numerical investigation

“…For it to sit at the critical tide, M µ ∼ 2 × 10 −3 . The timescale τ for growth of clouds via superradiance is of order τ ∼ (M µ) −9 M [6], too large to be meaningful for scalar fields, but potentially affecting vectors (τ ∼ (M µ) −7 M ) [33,36,37]. The tide is also small enough that it should not be affecting any of the constraints derived from the possible non-observation of GWs from the system [38,39].…”

New application of the Killing vector field formalism: modified periodic potential and two-level profiles of the axionic dark matter distribution

“…First of all, we mean the non-minimal extensions of the axion models, which are based on the F (R) modifications of the theory of gravity (see, e.g., [17][18][19][20][21]), on the non-minimal extensions of the theory of the axion-photon coupling [22], and on the axionically extended models of the dynamic aether [23]. The second trend is associated with the recent surge of interest to the black hole mergers and supermassive black holes: the axionic dark matter can play the role of * Electronic address: Alexander.Balakin@kpfu.ru † Electronic address: groshevdmitri@mail.ru a marker revealing specific features of the strong gravitational field (see, e.g., [24,25] as illustrations). The third trend is connected with the modeling of axionic structures of different scales, associated with the galactic halos, miniclusters, halos surrounding the magnetars, dyons, etc.…”