Related papers: Evolving black hole with scalar field accretion
We study the classical dynamics of black holes during a nonsingular cosmological bounce. Taking a simple model of a nonsingular bouncing cosmology driven by the combination of a ghost and ordinary scalar field, we use nonlinear evolutions…
In this short talk we review our results from the paper hep-th/0604075 with the main stress on the issues of causality and acoustic metric in eikonal approximation. In addition we correct the formula for the redshift of sound signals from…
A spherically symmetric black hole solution defined by the gravitational mass is explored in higher-order curvature gravity associated with a scalar field. It is demonstrated that the singularities of the curvature invariants will be far…
Combining deeper insight of Einstein's equations with sophisticated numerical techniques promises the ability to construct accurate numerical implementations of these equations. We illustrate this in two examples, the numerical evolution of…
Novel static black hole solutions with electric and magnetic charges are derived for the class of modified gravities: $f({\cal R})={\cal R}+2\beta\sqrt{{\cal R}}$, with or without a cosmological constant. The new black holes behave…
In this paper we investigate a steady accretion within the Einstein-Straus vacuole, in the presence of the cosmological constant. The dark energy damps the mass accretion rate and --- above certain limit --- completely stops the steady…
The spectrum of known black-hole solutions to the stationary Einstein equations has been steadily increasing, sometimes in unexpected ways. In particular, it has turned out that not all black-hole-equilibrium configurations are…
The formation of massive black holes and their coevolution with host galaxies are pivotal areas of modern astrophysics. Spherical accretion onto a central point mass serves as a foundational framework in cosmological simulations,…
The discovery of cosmic acceleration has presented a unique challenge for cosmologists. As observational cosmology forges ahead, theorists have struggled to make sense of a standard model that requires extreme fine tuning. This challenge is…
Near an event horizon, the action of general relativity acquires a new asymptotic conformal symmetry. Using two-dimensional dilaton gravity as a test case, I show that this symmetry results in a chiral Virasoro algebra with a calculable…
We consider Einstein gravity in general dimensions, coupled to a scalar field either minimally or non-minimally, together with a generic scalar potential. By making appropriate choices of the scalar potential, we obtain large classes of new…
We study the dynamics of spherically symmetric black holes in scalar Gauss-Bonnet gravity with an additional coupling between the scalar field and the Ricci scalar using non-linear simulations that employ excision. In this class of…
We present a code for solving the coupled Einstein-hydrodynamics equations to evolve relativistic, self-gravitating fluids. The Einstein field equations are solved in generalized harmonic coordinates on one grid using pseudospectral…
In this work we obtain a numerical self-consistent spherical solution of the semiclassical Einstein equations representing the evaporation of a trapped region which initially has both an outer and an inner horizon. The classical matter…
In previous work, we derived the most general solution of the collisionless Boltzmann equation describing the accretion of a kinetic gas into a Schwarzschild black hole background, and we gave explicit expressions for the corresponding…
In our program of studying numerically the so-called Bondi-Hoyle accretion in the fully relativistic regime, we present here first results concerning the evolution of matter accreting supersonically onto a rotating (Kerr) black hole. These…
We discuss the new class of static axially symmetric black hole solutions obtained recently in Einstein-Yang-Mills and Einstein-Yang-Mills-dilaton theory. These black hole solutions are asymptotically flat and they possess a regular event…
This work addresses and solves the problem of generically tracking black hole event horizons in computational simulation of black hole interactions. Solutions of the hyperbolic eikonal equation, solved on a curved spacetime manifold…
Exact static, spherically symmetric solutions to the Einstein-Maxwell-scalar equations, with a dilatonic-type scalar-vector coupling, in $D$-dimensional gravity with a chain of $n$ Ricci-flat internal spaces are considered. Their properties…
We provide a description of a thin accretion disc for a static spherically symmetric black holes in $f(R)$ gravity. In this regard, we first study the horizons of black holes in $f(R)$ gravity. The equation of motion and effective potential…