Related papers: Probing supermassive black hole scalarization with…
We investigate the orbital structure and observable appearance of rotating Kerr black holes endowed with synchronized scalar hair described by two time-periodic scalar fields with a flat target-space geometry. The presence of scalar hair…
Supermassive black holes (SMBHs) are tiny in comparison to the galaxies they inhabit, yet they manage to influence and coevolve along with their hosts. Evidence of this mutual development is observed in the structure and dynamics of…
We construct a family of asymptotically flat, rotating black holes with scalar hair and a regular horizon, within five dimensional Einstein's gravity minimally coupled to a complex, massive scalar field doublet. These solutions are…
In this review we focus our attention on scalar-tensor gravity models and their empirical verification in terms of black hole and wormhole physics. We focus on a black hole, embedded in an expanding universe, describing both cosmological…
An astrophysical population of supermassive black hole binaries is thought to be the strongest source of gravitational waves in the frequency range covered by Pulsar Timing Arrays (PTAs). A potential cause for concern is that the standard…
In classical general relativity astrophysical black holes can be affected by the superradiant instability when gravity is minimally coupled to a light bosonic field. The majority of phenomenological studies have focused on the idealized…
It was recently shown that a scalar field suitably coupled to the Gauss-Bonnet invariant $\mathcal{G}$ can undergo a spin-induced linear tachyonic instability near a Kerr black hole. This instability appears only once the dimensionless spin…
Hypothetical light scalar particles trigger the superradiant instability around spinning black holes (BHs), causing clouds of scalars to grow around the BH. In the presence of sufficiently strong particle self-interactions (characterized by…
We present explicit black holes endowed with primary scalar hair within the shift-symmetric subclass of Beyond Horndeski theories. These solutions depend, in addition to the conventional mass parameter, on a second free parameter encoding…
Binary pulsars provide some of the tightest current constraints on modified theories of gravity and these constraints will only get tighter as radio astronomers continue timing these systems. These binary pulsars are particularly good at…
We show that scalar hair can be added to rotating, vacuum black holes of general relativity. These hairy black holes (HBHs) clarify a lingering question concerning gravitational solitons: if a black hole can be added at the centre of a…
Galaxy observations suggest that mergers of supermassive black hole binaries (SMBHBs) are rare events, with rates of order one per decade across the observable Universe. We present a framework to search for merging SMBHBs in pulsar timing…
Twenty years have passed since the discovery of the accelerated expansion of the Universe, reviving the interest for alternative theories of gravity. Adding a scalar degree of freedom to the usual metric of general relativity is one of the…
Recently new scalarized black hole solutions were constructed in the extended scalar-tensor-Gauss-Bonnet gravity, where the scalar field is sourced by the curvature of the spacetime via the Gauss-Bonnet invariant. A natural extension of…
We investigate the spontaneous scalarization of charged Taub-NUT black holes within the framework of Einstein-Maxwell-scalar-Gauss-Bonnet gravity. By selecting a suitable coupling function, the theory admits the analytic charged Taub-NUT…
The no-hair theorem postulates that the only externally observable properties of a black hole are its mass, its electric charge, and its angular momentum. In scalar-tensor theories of gravity, a matter distribution around a black hole can…
We introduce a technique for gravitational-wave analysis, where Gaussian process regression is used to emulate the strain spectrum of a stochastic background using population-synthesis simulations. This leads to direct Bayesian inference on…
Extended scalar-tensor-Gauss-Bonnet (eSTGB) gravity has been recently argued to exhibit spontaneous scalarisation of vacuum black holes (BHs). A similar phenomenon can be expected in a larger class of models, which includes e.g.…
It has been shown recently that the charged black hole can be scalarized if Maxwell field minimally couples with a complex scalar which has nonnegative nonlinear potential. We firstly prove that such scalarization cannot be a result of…
We parametrize a large class of corrections to general relativity which include a long-ranged gravitational scalar field as a dynamical degree of freedom in two ways: parametrizing the structure of the correction to the action, and…