Related papers: Absorption cross section in de Sitter space
We study the evolution of charged, asymptotically de Sitter black holes close to the cold extremal branch of the phase space. We consider black hole sizes that are parametrically smaller than both their inverse temperature and the…
The problem of the one-exciton absorption spectrum is considered for the lattice of two-level interacting atoms whose initial energy splitting depends on the coordinate. It is shown that for some types of interatomic interaction, this…
Using a static massive spherically symmetric scalar field coupled to gravity in the Schwarzschild-de Sitter (SdS) background, first we consider some asymptotic solutions near horizon and their local equations of state(E.O.S) on them. We…
The infrared range optical absorption mechanism of Carbon-Copper composite thin layer coated on the Diamond-Like Carbon (DLC) buffer layer has been investigated. By consideration of weak interactions between copper nanoparticles in their…
An introductory, self-contained overview, with pedagogical figures, is provided to acquaint readers unfamiliar with the subjects with key aspects of de Sitter space and inflation. The connection between de Sitter space and cosmology is…
We discuss issues relating to the topology of Euclidean de Sitter space. We show that in (2+1) dimensions, the Euclidean continuation of the`causal diamond', i.e the region of spacetime accessible to a timelike observer, is a…
Building on previous work on de Sitter extremal surfaces anchored at the future boundary, we study no-boundary extremal surfaces in slow-roll inflation models, with perturbations to no-boundary global $dS$ preserving the spatial isometry.…
Irreversible adsorption of spheres on flat collectors having dimension $d<2$ is studied. Molecules are adsorbed on Sierpinski's Triangle and Carpet like fractals ($1<d<2$), and on General Cantor Set ($d<1$). Adsorption process is modeled…
Adapting Mourre's commutator method to the dissipative setting, we prove a limiting absorption principle for a class of abstract dissipative operators. A consequence is the resolvent estimates for the high frequency Helmholtz equation when…
The absorption of infrared and visible radiation from stellar emission spectra by the negatively charged hydrogen ions H$^{-}$ is considered. We derive the explicit formulas for the bound-free absorption coefficient $a_{\nu}$ for the…
Following arXiv:1501.03019 [hep-th], we study de Sitter space and spherical subregions on a constant boundary Euclidean time slice of the future boundary in the Poincare slicing. We show that as in that case, complex extremal surfaces exist…
We consider a real scalar field in de Sitter background and compute its thermal propagators. We propose that in a dS/CFT context, non-trivial thermal effects as seen by an 'out' observer can be encoded in the anomalous dimensions of the $d…
Photoabsorption of atomic oxygen in the energy region below the $\rm 1s^{-1}$ threshold in x-ray spectroscopy from {\it Chandra} and {\it XMM-Newton} is observed in a variety of x-ray binary spectra. Photoabsorption cross sections…
Aims: We present observations from the Interface Region Imaging Spectrograph (IRIS) of absorption features from a multitude of cool atomic and molecular lines within the profiles of Si IV transition region lines. Many of these spectral…
In this paper we show that the entropy of cosmological horizon in 4-dimensional Topological Kerr-Newman-de Sitter spaces can be described by the Cardy-Verlinde formula, which is supposed to be an entropy formula of conformal field theory in…
We discuss how measurements of fluctuations in the absorption of cosmic microwave background (CMB) photons by neutral gas during the cosmic dark ages, at redshifts z ~ 7--200, could reveal the primordial deuterium abundance of the Universe.…
We study, using Mean Curvature Flow methods, 3+1 dimensional cosmologies with a positive cosmological constant, matter satisfying the dominant and the strong energy conditions, and with spatial slices that can be foliated by 2-dimensional…
The ability to efficiently absorb thermal radiation within a small material volume is crucial for the realization of compact and high spatial resolution thermal imagers. Here we propose and experimentally demonstrate a compact plasmonic…
In {\em Nucl. Phys.} B {\bf 615}, 285 (2001) [arXiv:hep-th/0107113], the wave equation for a minimally coupled scalar was studied in the geometry of a D1-D5 system with non-zero angular momentum. The probability for a quantum to enter the…
We consider a d-dimensional spherically symmetric dilatonic R^2 string corrected black hole solution. We study its stability under tensor type gravitational perturbations and compute the absorption cross section for low frequency…