Related papers: Estimate of the superradiance spectrum in dispersi…
We develop a definitive physical-space scattering theory for the scalar wave equation on Kerr exterior backgrounds in the general subextremal case |a|<M. In particular, we prove results corresponding to "existence and uniqueness of…
Recent polarized neutron scattering experiments on $YBa_2 Cu_3 O_7$ have revealed a sharp spectral peak at the $(\pi,\pi)$ in reciprocal lattice centered around the energy transfer of $41\ meV$. We offer a theoretical explanation of this…
The reflection spectrum produced by a cold medium illuminated by X-ray photons is not isotropic and its shape depends on the emission angle. In the reflection spectrum of an accretion disk of a black hole, the value of the emission angle…
The amplification of radiation by superradiance is a universal phenomenon observed in numerous physical systems. We demonstrate that superradiant scattering generates entanglement for different input states, including coherent states,…
We present a method for computing the spectrum of black hole radiation of a scalar field satisfying a wave equation with high frequency dispersion. The method involves a combination of Laplace transform and WKB techniques for finding…
Hawking radiation, despite being known to theoretical physics for nearly forty years, remains elusive and undetected. It also suffers, in its original context of gravitational black holes, from practical and conceptual difficulties. Of…
Extending a computation which appeared recently in hep-th/0301173, we compute the transmission and reflection coefficients for massless uncharged scalars and gravitational waves scattered by d>=4 Schwarzschild or d=4 Reissner-Nordstrom…
In the scattering picture, thermal radiation effects may be associated with the `above barrier' reflection coefficient, which comes into play because of complex turning points. This note contains several general remarks on the application…
We study the neutrino scattering off a rotating black hole with a realistic accretion disk permeated by an intrinsic magnetic field. Neutrino trajectories in curved spacetime as well as the particle spin evolution in dense matter of an…
We report a detailed and systematic numerical study of wave propagation through a coherently amplifying random one-dimensional medium. The coherent amplification is modeled by introducing a uniform imaginary part in the site energies of the…
Spectroscopy is a unique experimental tool for measuring the fundamental Casimir-Polder interaction between excited state atoms, or other polarizable quantum objects, and a macroscopic surface. Spectroscopic measurements probe atoms at…
Local and non-local properties of Hawking radiation in the presence of short distance dispersion are computed using connection formulae. The robustness of the spectrum and that of the two-point function are explained by showing that the…
In this work, by a novel approach to studying the scattering of a Schwarzschild black hole, the non-commutativity is introduced as a perturbation. We begin by reformulating the Klein-Gordon equation for the scalar field in a new form that…
A strong light pulse propagating in a nonlinear Kerr medium produces a change in the refractive index, which makes light travel at different speeds inside and outside the pulse. By tuning the pulse velocity, an analog black hole horizon can…
Motivated by recent experimental progress, we study scalar wave propagation over an imperfect draining vortex, which can serve as an analogue for rotating and non-rotating extreme compact objects (ECOs). We encapsulate the absorbing…
We have investigated electromagnetically induced transparency in the spectrum of selective reflection at the interface of Rb atom vapors and a dielectric nanocell window. A nanocell with atomic vapor column thicknesses ranging from 150 to…
Takahashi & Soda (2010 Class. Quantum Grav. v27 p175008, arXiv:1005.0286) have recently considered the effect (at lowest non-trivial order) of dynamical, quantized gravitational fluctuations on the spectrum of scalar Hawking radiation from…
In this thesis we study the phenomenon of superradiance and its implications to the stability of black-holes (BH) and perfect-fluid stars. Superradiance is a radiation enhancement process that involves rotating dissipative systems. In BH…
Classically, reflectionless kinks transmit all incident radiation. Recently, we have used an analyticity argument together with a solution of the Lippmann-Schwinger equation to write down the leading quantum correction to the reflection…
Hawking radiation is the proposed thermal black-body radiation of quantum nature emitted from a black hole. One common way to give an account of Hawking radiation is to consider a detector that follows a static trajectory in the vicinity of…