Constraining Black Holes with Light Boson Hair and Boson Stars using Epicyclic Frequencies and QPOs

Abstract

Light bosonic fields are ubiquitous in extensions of the Standard Model. Even when minimally coupled to gravity, these fields might evade the assumptions of the black-hole no-hair theorems and give rise to spinning black holes which can be drastically different from the Kerr metric. Furthermore, they allow for self-gravitating compact solitons, known as (scalar or Proca) boson stars. The quasi-periodic oscillations (QPOs) observed in the X-ray flux emitted by accreting compact objects carry information about the strong-field region, thus providing a powerful tool to constrain deviations from Kerr's geometry and to search for exotic compact objects. By using the relativistic precession model as a proxy to interpret the QPOs in terms of geodesic frequencies, we investigate how the QPO frequencies could be used to test the no-hair theorem and the existence of light bosonic fields near accreting compact objects. We show that a detection of two QPO triplets with current sensitivity can already constrain these models, and that the future eXTP mission or a LOFT-like mission can set very stringent constraints on black holes with bosonic hair and on (scalar or Proca) boson stars. The peculiar geodesic structure of compact scalar/Proca boson stars implies that these objects can easily be ruled out as alternative models for X-ray source GRO J1655-40.

16 pages, 10 figures; v2: revised version containing an improved discussion and one new plot; v3: minor changes to match published version

References in corpus (10)

• Ultralight scalars as cosmological dark matter
• Black holes as particle detectors: evolution of superradiant instabilities
• Testing the black hole "no-hair" hypothesis
• Models of rotating boson stars and geodesics around them: new type of orbits
• Testing Gravity with Quasi Periodic Oscillations from accreting Black Holes: the Case of Einstein-Dilaton-Gauss-Bonnet Theory
• Scalarized Hairy Black Holes
• Iron K$\alpha$ line of Kerr black holes with scalar hair
• Kerr-Newman black holes with scalar hair
• Iron K$\alpha$ line of boson stars
• Viscous Driving of Global Oscillations in Accretion Discs Around Black Holes

Cited by in corpus (19)

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• The imitation game: Proca stars that can mimic the Schwarzschild shadow
• On the dynamical bar-mode instability in spinning bosonic stars
• Quasiperiodic oscillations around hairy black holes in Horndeski gravity
• Geodesic models of quasi-periodic-oscillations as probes of quadratic gravity
• An Ultralight Axion in Supersymmetry and Strings and Cosmology at Small Scales
• Extreme-mass-ratio inspirals into rotating boson stars: nonintegrability, chaos, and transient resonances
• Black holes with synchronised Proca hair: linear clouds and fundamental non-linear solutions
• Kerr black holes with synchronised scalar hair and higher azimuthal harmonic index
• Kerr black holes with synchronised axionic hair
• Gravitating solitons and black holes with synchronised hair in the four dimensional O(3) sigma-model
• Equatorial extreme-mass-ratio inspirals in Kerr black holes with scalar hair spacetimes
• Testing No-Hair Theorem by Quasi-Periodic Oscillations: the quadrupole of GRO J1655$-$40
• Iron K$\alpha$ line of Proca stars
• Bondi-Hoyle-Lyttleton accretion onto a rotating black hole with ultralight scalar hair
• High precision numerical sequences of rotating hairy black holes
• Constraining Cubic Curvature Corrections to General Relativity with Quasi-Periodic Oscillations