Related papers: PP-wave Black holes and The Matrix Model
We provide an informal discussion of pattern formation in a finite universe. The global size and shape of the universe is revealed in the pattern of hot and cold spots in the cosmic microwave background. Topological pattern formation can be…
We investigate a condensed matter ``black hole'' analogue, taking the Gross-Pitaevskii (GP) equation as a starting point. The linearized GP equation corresponds to a wave equation on a black hole background, giving quasinormal modes under…
A pair of simple wave equations is presented for the symmetric gravitational and electromagnetic perturbations of a charged black hole. One of the equations is uncoupled, and the other has a source term given by the solution of the first…
Theories of large extra dimensions (LEDs) such as the Arkani-Hamed, Dimopoulos & Dvali scenario predict a "true" Planck scale $M_\star$ near the TeV scale, while the observed $M_{pl}$ is due to the geometric effect of compact extra…
We investigate the passivity constraints on the relations between transmission, reflection, and absorption eigenvalues in linear time-invariant systems. Using techniques from matrix analysis, we derive necessary and sufficient conditions…
Gravitational waves from binary black hole mergers provide a glimpse of gravitational dynamics in its most extreme observable regime, potentially enabling precision tests of general relativity (GR) and of the Kerr description of black…
We consider massless scalar field perturbations of regular black holes in quasi-topological gravity. After reviewing various regular black hole solutions, we compute the total absorption cross-section and the partial absorption…
The bosonic content of string theory in curved background of multidimensional structure with p-branes has a systematic geometrical description as an effective sigma-model of gravity in lower dimension (say 3+1) with additional interacting…
A pp-wave is a Lorentzian manifold with a parallel light-like vector field satisfying a certain curvature condition. We introduce generalisations of pp-waves, on one hand by allowing the vector field to be recurrent and on the other hand by…
In the s-wave approximation the 4D Einstein gravity with scalar fields can be reduced to an effective 2D dilaton gravity coupled nonminimally to the matter fields. We study the leading order (tree level) vertices. The 4-particle matrix…
From the postulate that a black hole can be replaced by a boundary on the apparent horizon with suitable boundary conditions, an unconventional scenario for the evolution emerges. Only an insignificant fraction of energy of order…
We study extensions of N-wave systems with PT-symmetry. The types of (nonlocal) reductions leading to integrable equations invariant with respect to P- (spatial reflection) and T- (time reversal) symmetries is described. The corresponding…
We show that primordial black holes (PBHs) in the $\textit{Stupendously Large Black Hole}$ mass range ($M \gtrsim 10^{11}\,M_\odot$) produce isocurvature perturbations exceeding current $\textit{Planck}$ Cosmic Microwave Background limits,…
We examine a model of BPS black holes lying on a discrete extra space. The geometry is obtained from the discretization of the harmonic equation. We study the scattering amplitudes of two types of scalar fields, which correspond to fields…
We describe a large class of solutions in pure gravity, dilaton gravity and supergravity corresponding to extended higher-dimensional black holes with strong (non-linear) gravitational waves propagating along their worldvolume. For pure…
Primordial black holes still represent a viable candidate for a significant fraction, if not for the totality, of dark matter. If these compact objects have masses of order tens of solar masses, their coalescence can be observed by current…
In our article we consider some algebraical methods which may be useful in some inverse spectral problems. The reconstraction of the matrix from its minors is considered.
We study realistic models predicting primordial black hole (PBH) formation from density fluctuations generated in a first-order phase transition. We show that the second-order correction in the expansion of the bubble nucleation rate is…
In this work, we investigate the feasibility of using ringdown waveforms from supermassive black holes immersed in dark-matter halos to extract both the intrinsic black-hole parameters and those characterizing the surrounding matter…
Tangles of loops which approximate an aspect of the Kerr-Newman black hole metrics at large scales compared to the Planck length are constructed. The physical aspect the tangles approximate is discussed. This construction may be useful in…