Stationary configurations around charged rotating black holes

Scalar fields can form real bound states around black holes for a specific frequency. In this work, we review the case of a charged and massive scalar field around a charged rotating black hole, in order to find these bound states. We analyze the behavior of these solutions for different parameters and also comment on analytic solutions for certain regimes.

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Massive scalar field perturbation on Kerr black holes in dynamical Chern–Simons gravity

The European Physical Journal C ◽

10.1140/epjc/s10052-021-09249-8 ◽

2021 ◽

Vol 81 (5) ◽

Author(s):

Shao-Jun Zhang

Keyword(s):

Black Holes ◽

Black Hole ◽

Scalar Field ◽

Massive Scalar ◽

Coupling Constant ◽

Field Mass ◽

Field Perturbation ◽

Massive Scalar Field ◽

Kerr Black Holes ◽

Chern Simons

AbstractWe study massive scalar field perturbation on Kerr black holes in dynamical Chern–Simons gravity by performing a $$(2+1)$$ ( 2 + 1 ) -dimensional simulation. Object pictures of the wave dynamics in time domain are obtained. The tachyonic instability is found to always occur for any nonzero black hole spin and any scalar field mass as long as the coupling constant exceeds a critical value. The presence of the mass term suppresses or even quench the instability. The quantitative dependence of the onset of the tachyonic instability on the coupling constant, the scalar field mass and the black hole spin is given numerically.

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Instability of charged massive scalar fields in bound states around Kerr–Sen black holes

International Journal of Modern Physics D ◽

10.1142/s0218271815501023 ◽

2015 ◽

Vol 24 (14) ◽

pp. 1550102 ◽

Cited By ~ 14

Author(s):

Haryanto M. Siahaan

Keyword(s):

Black Holes ◽

Bound States ◽

Gordon Equation ◽

Scalar Fields ◽

Bound State ◽

Imaginary Component ◽

Scalar Perturbation ◽

Massive Scalar ◽

Massive Scalar Field ◽

Klein Gordon

In this paper, we show the instability of a charged massive scalar field in bound states around Kerr–Sen black holes. By matching the near and far region solutions of the radial part in the corresponding Klein–Gordon equation, one can show that the frequency of bound state scalar fields contains an imaginary component which gives rise to an amplification factor for the fields. Hence, the unstable modes for a charged and massive scalar perturbation in Kerr–Sen background can be shown.

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Stationary bound states of massless scalar fields around black holes and black hole analogues

International Journal of Modern Physics D ◽

10.1142/s0218271815420183 ◽

2015 ◽

Vol 24 (09) ◽

pp. 1542018 ◽

Cited By ~ 5

Author(s):

Carolina L. Benone ◽

Luís C. B. Crispino ◽

Carlos A. R. Herdeiro ◽

Eugen Radu

Keyword(s):

Black Holes ◽

Black Hole ◽

Spatial Distribution ◽

Scalar Field ◽

Bound States ◽

Neumann Boundary ◽

Mass Term ◽

Scalar Fields ◽

Massless Scalar ◽

Field System

We discuss stationary bound states, a.k.a. clouds, for a massless test scalar field around Kerr black holes (BHs) and spinning acoustic BH analogues. In view of the absence of a mass term, the trapping is achieved via enclosing the BH — scalar field system in a cavity and imposing Dirichlet or Neumann boundary conditions. We discuss the variation of these bounds states with the discrete parameters that label them, as well as their spatial distribution, complementing results in our previous work [C. L. Benone, L. C. B. Crispino, C. Herdeiro and E. Radu, Phys. Rev. D91 (2015) 104038].

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A new spin on black hole hair

International Journal of Modern Physics D ◽

10.1142/s0218271814420140 ◽

2014 ◽

Vol 23 (12) ◽

pp. 1442014 ◽

Cited By ~ 71

Author(s):

Carlos A. R. Herdeiro ◽

Eugen Radu

Keyword(s):

Black Holes ◽

General Relativity ◽

Black Hole ◽

Scalar Field ◽

Massive Scalar ◽

Massive Scalar Field ◽

Hairy Black Holes ◽

Scalar Hair

We show that scalar hair can be added to rotating, vacuum black holes (BHs) of general relativity. These hairy black holes (HBHs) clarify a lingering question concerning gravitational solitons: Whether a BH can be added at the centre of a boson star (BS), as it typically can for other solitons. We argue that it can, but only if it is spinning. The existence of such HBHs is related to the Kerr superradiant instability triggered by a massive scalar field. This connection leads to the following conjecture: a (hairless) BH, which is afflicted by the superradiant instability of a given field, must allow hairy generalizations with that field.

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Gauss–Bonnet black holes supporting massive scalar field configurations: the large-mass regime

The European Physical Journal C ◽

10.1140/epjc/s10052-019-7494-9 ◽

2019 ◽

Vol 79 (11) ◽

Cited By ~ 5

Author(s):

Shahar Hod

Keyword(s):

Black Holes ◽

Black Hole ◽

Scalar Field ◽

Coupling Parameter ◽

Analytical Formula ◽

Analytical Techniques ◽

Scalar Fields ◽

Large Field ◽

Massive Scalar Field ◽

Black Hole Spacetimes

AbstractIt has recently been demonstrated that black holes with spatially regular horizons can support external scalar fields (scalar hairy configurations) which are non-minimally coupled to the Gauss–Bonnet invariant of the curved spacetime. The composed black-hole-scalar-field system is characterized by a critical existence line $$\alpha =\alpha (\mu r_{\text {H}})$$α=α(μrH) which, for a given mass of the supported scalar field, marks the threshold for the onset of the spontaneous scalarization phenomenon [here $$\{\alpha ,\mu ,r_{\text {H}}\}$${α,μ,rH} are respectively the dimensionless non-minimal coupling parameter of the field theory, the proper mass of the scalar field, and the horizon radius of the central supporting black hole]. In the present paper we use analytical techniques in order to explore the physical and mathematical properties of the marginally-stable composed black-hole-linearized-scalar-field configurations in the eikonal regime $$\mu r_{\text {H}}\gg 1$$μrH≫1 of large field masses. In particular, we derive a remarkably compact analytical formula for the critical existence-line $$\alpha =\alpha (\mu r_{\text {H}})$$α=α(μrH) of the system which separates bare Schwarzschild black-hole spacetimes from composed hairy (scalarized) black-hole-field configurations.

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Spin-induced scalarization of Kerr black holes with a massive scalar field

The European Physical Journal C ◽

10.1140/epjc/s10052-020-08765-3 ◽

2020 ◽

Vol 80 (12) ◽

Author(s):

Daniela D. Doneva ◽

Lucas G. Collodel ◽

Christian J. Krüger ◽

Stoytcho S. Yazadjiev

Keyword(s):

Black Holes ◽

Black Hole ◽

Scalar Field ◽

Coupling Parameter ◽

Kerr Black Hole ◽

Instability Region ◽

Perturbation Equation ◽

Massive Scalar ◽

Field Mass ◽

Massive Scalar Field

AbstractIn the present paper we study the onset of the spin-induced scalarization of a Kerr black hole in scalar-Gauss–Bonnet gravity with a massive scalar field. Our approach is based on a $$(2+1)$$ ( 2 + 1 ) time evolution of the relevant linearized scalar field perturbation equation. We examine the region where the Kerr black hole becomes unstable giving rise to new scalarized rotating black holes with a massive scalar field. With increasing of the scalar field mass, the minimum value of the Gauss–Bonnet coupling parameter at which scalarization is possible, increases and thus the instability region shrinks. Interestingly, the introduction of scalar field mass does not change the critical minimal value of the black hole angular momentum $$a_{\mathrm{crit}}/M$$ a crit / M where the instability of the Kerr black hole develops.

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