Related papers: Dynamical descalarization in binary black hole mer…
We consider an augmented Einstein-Maxwell-scalar model including an axionic-type coupling between the scalar and electromagnetic field. We study dyonic black hole solutions in this model. For the canonical axionic coupling emerging from…
Binary black holes may form both through isolated binary evolution and through dynamical interactions in dense stellar environments. The formation channel leaves an imprint on the alignment between the black hole spins and the orbital…
In this short review we describe some of the latest endeavours to understand the activity around Black Holes. First, it has been possible to demonstrate that a large part of the electromagnetic emission observed can be interpreted as…
We numerically construct asymptotically extremal black holes through the nonlinear evolution of a charged scalar field. Our procedure -- which extends the work of Murata-Reall-Tanahashi to include charged scalar dynamics -- involves the…
Hierarchical structure formation inevitably leads to the formation of supermassive binary black holes (BBHs) with a sub-parsec separation in galactic nuclei. However, to date there has been no unambiguous detection of such systems. In an…
Recently, by considering nontrivial couplings between scalar fields and the Gauss-Bonnet invariant, the Schwarzschild black hole may allow regular scalar hairy configurations. The numerical studies of this spontaneous scalarization…
It was believed that when gravitational, electromagnetic and scalar waves interact, a spacelike curvature singularity or Cauchy horizon develops because of mutual focusing. We show with an exact solution that the collision of…
We study spontaneous scalarization of electrically charged extremal black holes in $D\geq 4$ spacetime dimensions. Such a phenomenon is caused by the symmetry breaking due to quartic interactions of the scalar -- Higgs potential and…
The study of the interaction of a massive black hole binary with its gaseous environment is crucial in order to be able to predict merger rates and possible electromagnetic counterparts of gravitational wave signals. The evolution of the…
Binary black holes can form efficiently in dense young stellar clusters, such as the progenitors of globular clusters, via a combination of gravitational segregation and cluster evaporation. We use simple analytic arguments supported by…
Stellar mass black holes are formed in the field, and are observed in binaries. Population synthesis estimates for the formation of BH-PSR binaries suggest these may be observed, but with very large formal uncertainties in the formation…
In galactic centers, stars and binaries can be injected into low-angular-momentum orbits, resulting in close encounters with the central supermassive black hole (SMBH). Previous works have shown that under different conditions, such close…
We study the Einstein-Euler-Heisenberg theory in the presence of a self interacting scalar field, minimally coupled to gravity. We solve analytically the field equations for the magnetically charged case and we obtain novel magnetically…
We study the dynamical formation of scalar monopole and dipole hair in scalar Gauss-Bonnet theory and dynamical Chern-Simons theory. We prove that the spherically-symmetric mode of the dipole hair is completely determined by the product of…
Coalescing massive black hole binaries are produced by the mergers of galaxies. The final stages of the black hole coalescence produce strong gravitational radiation that can be detected by the space-borne LISA. In cases where the black…
Supermassive black holes are expected to pair as a result of galaxy mergers, and form a bound binary at parsec or sub-parsec scales. These scales are unresolved even in nearby galaxies, and thus detection of non-active black hole binaries…
Based on the consideration of potential energy of the di-black-hole as a function of mass asymmetry (transfer) collective coordinate, the possibility of matter transfer between the black holes in a binary system is investigated. The…
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.…
We investigated the critical dynamical scalarization and descalarization of black holes within the framework of the Einstein-Maxwell-scalar theory featuring higher-order coupling functions. Both the critical scalarization and…
We discuss the formation of scalar hair on Gauss-Bonnet solitons and black holes in 5-dimensional Anti-de Sitter (AdS) space-time. We present new results on the static case and point out further details. We find that the presence of the…