Related papers: Absorption Cross Section for S-wave massive Scalar
We present empirical scaling relations for the significance of absorption features detected in medium resolution, far-UV spectra obtained with the Cosmic Origins Spectrograph (COS). These relations properly account for both the extended…
We study the absorption and scattering of massless scalar waves by Frolov black holes, a regular deformation of the Reissner--Nordstr\"om geometry. A null-geodesic analysis provides the photon-sphere radius and the critical impact…
The reflection, transmission and absorption of a symmetric electromagnetic pulse, which carrying frequency is close to the frequency of an interband transition in a QW (QW), are obtained. The energy levels of a QW are assumed discrete, one…
We study the absorption of plane waves by Kerr black holes. We calculate the absorption cross section: the area of the black hole shadow at a finite wavelength. We present a unified picture of the absorption of all massless bosonic fields,…
We investigate the absorption of massless scalar, electromagnetic, and gravitational fields propagating in the Schwarzschild black hole geometry. Using complex angular momentum techniques, we first derive a representation of the absorption…
The new manifestation of conformal invariance for a massless scalar particle in a Riemannian spacetime of general relativity is found. Conformal transformations conserve the Hamiltonian and wave function in the Foldy-Wouthuysen…
This paper investigates scalar field perturbations coupled to the Einstein tensor of non-commutative black holes . We compute the grey-body factors and absorption cross-sections for different choices of the parameters using the partial wave…
We discuss the propagation of scalars in a large class of non-extremal black hole and black p-brane geometries in generic dimensions. We show that the radial wave equation near the horizon possesses the SL(2,R) structure in every case;…
The classical scalar massive field satisfying the Klein-Gordon equation in a finite one-dimensional space interval of periodically varying length with Dirichlet boundary conditions is studied. For the sufficiently small mass, the energy can…
We consider the absorption of higher angular momentum modes of scalars into black holes, at low energies, and ask if the resulting cross sections are reproduced by a D-brane model. To get the correct dependence on the volume of the…
Linear and nonlinear optical absorption coefficients of the two-dimensional semiconductor ring in the perpendicular magnetic field $\bf B$ are calculated within independent electron approximation. Characteristic feature of the energy…
We present a study of scattering of massless planar scalar waves by a charged non-rotating black hole. Partial wave methods are applied to compute scattering and absorption cross sections, for a range of incident wavelengths. We compare our…
Motivated by the brane-world scenarios, we study the absorption problem when the spacetime background is $(4+n)$-dimensional Schwarzschild black hole. We compute the low-energy absorption cross sections for the brane-localized massive…
We investigate the low-frequency absorption cross section of the electromagnetic waves for the extreme Reissner-Nordstrom black holes in higher dimensions. We first construct the exact solutions to the relevant wave equations in the…
We study the absorption of massive spin-half particles by a small Schwarzschild black hole by numerically solving the single-particle Dirac equation in Painleve-Gullstrand coordinates. We calculate the absorption cross section for a range…
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…
The equivalence of inertial and gravitational masses is a defining feature of general relativity. Here, we clarify the status of the equivalence principle for interactions mediated by a universally coupled scalar, motivated partly by recent…
The Random Sequential Adsorption (RSA) problem holds crucial theoretical and practical significance, serving as a pivotal framework for understanding and optimizing particle packing in various scientific and technological applications. Here…
Medium effects as a function of the mass number $A$ are studied in the total photonuclear cross section from the $\Delta$-resonance region up to the region where shadowing effects are known to exist. A consistent picture is obtained by…
We analyze the annihilation cross section of dark matter which interacts with the standard model sector over the scalar unparticle propagator. We observe that the annihilation cross section of dark matter pair is sensitive to the dark…