Related papers: Geometric Bremsstrahlung in the Early Universe
A detection technique of ultra-high energy cosmic rays, complementary to the fluorescence technique, would be the use of the molecular Bremsstrahlung radiation emitted by low-energy electrons left after the passage of the showers in the…
Simple analytic formulas are considered for the energy radiated in low frequency bremsstrahlung from fully ionized gases. A formula that has been frequently cited over many years turns out to have only a limited range of validity, more…
Recently it has been suggested that thermal bremsstrahlung emission, when it decouples prior to recombination, creates an excess over the Planck cosmic microwave background spectrum at sub-GHz frequencies. Remarkable by itself, this would…
Primordial black holes which are created at the very early universe can get decayed in the matter dominated era and thus produce photons, hence resulting in dilution of the baryon asymmetry and evolution of the cosmological scale factor.…
We discuss the cosmological evolution of a 3-brane Universe in the presence of energy influx from the bulk. We show that this influx can lead to accelerated expansion on the brane, depending on the equations of state of the bulk and brane…
Using our previous approach to electromagnetic emission during tunneling, an explicit, essentially classical, formula describing the bremsstrahlung spectrum in alpha decay is derived. The role of tunneling motion in photon emission is…
Based on the formalism by Kaminker et al. (Astron. Astrophys. 343 (1999) 1009) we derive an analytic approximation for neutrino-pair bremsstrahlung emissivity due to scattering of electrons by atomic nuclei in the neutron star crust of any…
There has recently been interest in the role of inverse bremsstrahlung, the emission of photons by fast suprathermal ions in collisions with ambient electrons possessing relatively low velocities, in tenuous plasmas in various astrophysical…
We study the evolution of photon injections with a power-law type spectrum inserted at various epochs of the universe, and obtain constraints on their parameter space from multiple different cosmological probes. Our work is motivated by the…
Context. Explaining the accelerated expansion of the Universe is one of the fundamental challenges in physics today. Cosmography provides information about the evolution of the universe derived from measured distances, assuming only that…
We study the bremsstrahlung radiation of a tunneling charged particle in a time-dependent picture. In particular, we treat the case of bremsstrahlung during alpha-decay, which has been suggested as a promissing tool to investigate the…
The polarization of real photons emitted from early-time heavy-ion collisions is calculated, concentrating on the contribution from bremsstrahlung and quark-antiquark annihilation processes at leading order in the strong coupling. The…
A semi-classical model based on quantum time concepts is presented for the evaluation of bremsstrahlung emission probabilities in alpha decay of nuclei. The contribution to the bremsstrahlung emission from the different regions in tunneling…
Cosmic explosions dissipate energy into their surroundings on a very wide range of time-scales: producing shock waves and associated particle acceleration. The historical culprits for the acceleration of the bulk of Galactic cosmic rays are…
I make a review on the aplications of the Bohm-De Broglie interpretation of quantum mechanics to quantum cosmology. In the framework of minisuperspaces models, I show how quantum cosmological effects in Bohm's view can avoid the initial…
Cosmic acceleration may be the result of unknown physical processes involving either new fields in high energy physics or modifications of gravitation theory. In the latter case, such modifications are usually related to the existence of…
Kinetic equations for the process of multiphoton bremsstrahlung of electron in a matter have been used to derive the equations for the moments of distributions of electrons over the number of emitted photons and over the energy loss. The…
We theoretically investigate nonresonant spontaneous bremsstrahlung in the scattering of an electron by a nucleus in the field of two linearly polarized light waves propagating in the same direction in the general relativistic case. It is…
Geometric optics effectively describes the propagation of electromagnetic waves when the wavelength is much smaller than the characteristic length scale of the medium, making wave phenomena like diffraction negligible. As a result, light…
The expansion of our universe, when followed backward in time, implies that it emerged from a phase of huge density, the big bang. These stages are so extreme that classical general relativity combined with matter theories is not able to…