Survival of the black hole's Cauchy horizon under non-compact perturbations

We study numerically the evolution of spactime, and in particular of a spacetime singularity, inside a black hole under a class of perturbations of non-compact support. We use a very simplified toy model of a spherical charged black hole which is perturbed nonlinearly by a self-gravitating, spherical scalar field. The latter grows logarithmically with advanced time along an outgoing characteristic hypersurface. We find that for that class of perturbations a portion of the Cauchy horizon survives as a non-central, null singularity.Comment: 5 pages, 4 figure

Modeling of ion-implanted atoms diffusion during the epitaxial growth of the layer

The equation of impurity diffusion due to formation, migration, and dissolution of the pairs "impurity atom - intrinsic point defect" taking into account the nonuniform distributions of nonequilibrium point defects and drift of the pairs in the field of elastic stresses is presented in the coordinate system associated with the moving surface of the growing epitaxial layer. The analytical solution of this equation for the low fluence ion implantation has been obtained.Comment: 3 pages, 2 figure

Self force on particle in orbit around a black hole

We study the self force acting on a scalar charge in uniform circular motion around a Schwarzschild black hole. The analysis is based on a direct calculation of the self force via mode decomposition, and on a regularization procedure based on Ori's mode-sum regularization prescription. We find the four self-force at arbitrary radii and angular velocities (both geodesic and non-geodesic), in particular near the black hole, where general-relativistic effects are strongest, and for fast motion. We find the radial component of the self force to be repulsive or attractive, depending on the orbit.Comment: RevTeX, 4 pages, 4 Encapsulated PostScript figures. Submitted to Phys. Rev. Let

Singularity deep inside the spherical charged black hole core

We study analytically the spacelike singularity inside a spherically-symmetric, charged black hole coupled to a self-gravitating spherical massless scalar field. We assume spatial homogeneity, and find a generic solution in terms of a formal series expansion. This solution is tested against fully-nonlinear and inhomogeneous numerical simulations. We find full compliance between our analytical solution and the pointwise behavior of the singularity in the numerical simulations. This is a strong scalar-curvature monotonic spacelike singularity, which connects to a weak null singularity at asymptotically-late advanced time.Comment: 6 pages, to be published in Phys. Rev.

Orbital evolution of a test particle around a black hole: higher-order corrections

We study the orbital evolution of a radiation-damped binary in the extreme mass ratio limit, and the resulting waveforms, to one order beyond what can be obtained using the conservation laws approach. The equations of motion are solved perturbatively in the mass ratio (or the corresponding parameter in the scalar field toy model), using the self force, for quasi-circular orbits around a Schwarzschild black hole. This approach is applied for the scalar model. Higher-order corrections yield a phase shift which, if included, may make gravitational-wave astronomy potentially highly accurate.Comment: 4 pages, 3 Encapsulated PostScript figure

Self-forced gravitational waveforms for Extreme and Intermediate mass ratio inspirals

We present the first orbit-integrated self force effects on the gravitational waveform for an I(E)MRI source. We consider the quasi-circular motion of a particle in the spacetime of a Schwarzschild black hole and study the dependence of the dephasing of the corresponding gravitational waveforms due to ignoring the conservative piece of the self force. We calculate the cumulative dephasing of the waveforms and their overlap integral, and discuss the importance of the conservative piece of the self force in detection and parameter estimation. For long templates the inclusion of the conservative piece is crucial for gravitational-wave astronomy, yet may be ignored for short templates with little effect on detection rate. We then discuss the effect of the mass ratio and the start point of the motion on the dephasing.Comment: 9 pages, 15 figures. Substantially expanded and revised. We added: description of the orbits and analysis of the dependence of the dephasing effect on the parameter space, specifically the mass ratio and starting point of the motion. Also added a more thorough description of out metho

Singularity in 2+1 dimensional AdS-scalar black hole

We study the spacetime singularity in 2+1 dimensional AdS-scalar black hole with circular symmetry using a quasi-homogeneous model. We show that this is a spacelike, scalar curvature, deformationally strong singularity.Comment: 4 pages, RevTeX, submitted to PRD (brief report

On the falloff of radiated energy in black hole spacetimes

The goal of much research in relativity is to understand gravitational waves generated by a strong-field dynamical spacetime. Quantities of particular interest for many calculations are the Weyl scalar $\psi_4$, which is simply related to the flux of gravitational waves far from the source, and the flux of energy carried to distant observers, $\dot E$. Conservation laws guarantee that, in asympotically flat spacetimes, $\psi_4 \propto 1/r$ and $\dot E \propto 1/r^2$ as $r \to \infty$. Most calculations extract these quantities at some finite extraction radius. An understanding of finite radius corrections to $\psi_4$ and $\dot E$ allows us to more accurately infer their asymptotic values from a computation. In this paper, we show that, if the final state of the system is a black hole, then the leading correction to $\psi_4$ is ${\cal O}(1/r^3)$, and that to the energy flux is ${\cal O}(1/r^4)$ --- not ${\cal O}(1/r^2)$ and ${\cal O}(1/r^3)$ as one might naively guess. Our argument only relies on the behavior of the curvature scalars for black hole spacetimes. Using black hole perturbation theory, we calculate the corrections to the leading falloff, showing that it is quite easy to correct for finite extraction radius effects.Comment: 5 pages, no figures, accepted to Phys. Rev. D. This version corrects several typos and minor errors in the earlier submissio

Remarks on the formation of black holes in non-symmetric gravity

In a recent paper, we discussed the formation of black holes in non-symmetric gravity. That paper was then criticized by Cornish and Moffat. In the present paper, we address the arguments raised by Cornish and Moffat. In summary, we do not see any reason to doubt the validity of our former conclusions