Related papers: Geometric Bremsstrahlung in the Early Universe
The characteristic distribution of the matter in the universe and its observable expansion with apparent acceleration is the result of historical event - massive stellar explosions' radiation pressure on drifting particles of hydrogen…
We investigate the photon emission from the electrosphere of a quark star. It is shown that at temperatures $T\sim 0.1-1$ MeV the dominating mechanism is the bremsstrahlung due to bending of electron trajectories in the mean Coulomb field…
We present a calculation of neutrino pair bremsstrahlung due to electron-electron scattering in a relativistic degenerate plasma of electrons. Proper treatment of the in-medium photon propagator, i.e., inclusion of Debye screening of the…
Light millicharged particles can be copiously produced from meson decays in cosmic ray collisions with the atmosphere, leading to detectable signals in large underground neutrino detectors. In this paper we study a new channel for…
Being the largest gravitationally bound structures in the Universe, galaxy clusters are huge reservoirs of photons generated by the bremsstrahlung of a hot cluster gas. We consider the absorption of high-energy photons from distant…
The cross section for bremsstrahlung from highly relativistic particles is suppressed due to interference caused by multiple scattering in dense media, and due to photon interactions with the electrons in all materials. We present here a…
An injection of energy into the early Universe on a given characteristic length scale will result in turbulent motions of the primordial plasma. We calculate the stochastic background of gravitational radiation arising from a period of…
During the past two decades, cosmologists turned to particle physics in order to explore the physics of the very early Universe. The main link between the physics of the smallest and largest structures in the Universe is the idea of…
A brane universe moving in a curved higher dimensional bulk space is considered. The motion induces a cosmological evolution on the universe brane that is indistiguishable from a similar one induced by matter density on the brane. The…
In this paper the improved multipolar model of bremsstrahlung accompanied the $\alpha$-decay is presented. The angular formalism of calculations of the matrix elements, being enough complicated component of the model, is stated in details.…
We discuss a variety of bremsstrahlung processes associated with charged particles emitted by evaporating black holes. We show that such particles produce a negligible number of bremsstrahlung photons from their scattering off each other,…
The geometric transitions from the evolution in the complex plane of time provide channels for particle production for a quantum field in expanding universes. The production rate for one pair is obtained by squaring and summing the…
It is commonly assumed that the energy density of the Universe was dominated by radiation between reheating after inflation and the onset of matter domination 54,000 years later. While the abundance of light elements indicates that the…
We analyse the evolution of cosmological perturbations which leads to the formation of large voids in the distribution of galaxies. We assume that perturbations are spherical and all components of the Universe - radiation, matter and dark…
Using a new non-singular solution,it is shown that the production of photons in dilaton electrodynamics in a cosmological setting is increased if the effect of matter creation on the geometry is taken into account. This increment may be…
In massless scalar field cosmology, imposing the universe's physical volume as fundamentally discrete resolves the big bang singularity via a big bounce. We use quantum field theory on curved background to numerically track the number of…
One of the most striking examples for the production of particles out of the quantum vacuum due to external conditions is cosmological particle creation, which is caused by the expansion or contraction of the Universe. Already in 1939,…
We study the effect of multiple scatterings on the propagation of hard partons and the production of jet-bremsstrahlung photons inside a dense medium in the framework of deep-inelastic scattering off a large nucleus. We include the momentum…
The emission of direct (hard and thermal) photons from nucleon-nucleon Bremsstrahlung in heavy-ion collisions at Fermi energies is analyzed. We utilize a photon emission rate based on a quantum-field-theoretical model together with nucleon…
A detection technique for ultra-high energy cosmic rays, complementary to the fluorescence technique, would be the use of the molecular Bremsstrahlung radiation emitted by low-energy ionization electrons left after the passage of the…