Related papers: Geometric Bremsstrahlung in the Early Universe
Bremsstrahlung radiation is an important energy loss mechanism for energetic electrons in plasmas. In this paper we investigate the effect of bremsstrahlung radiation reaction on the electron distribution in 2D momentum space. We show that…
We discuss the possibility that gamma-ray bursts may result from cosmological relativistic blob emitting neutron star jets that precess past the line of sight. Beaming reduces the energy requirements, so that the jet emission can last…
In the present paper we investigate coherent bremsstrahlung of high energy electrons moving in a periodically deformed single crystal with a complex base. The formula for corresponding differential cross-section is derived for an arbitrary…
In the late 1990s, observations of type Ia supernovae led to the astounding discovery that the universe is expanding at an accelerating rate. The explanation of this anomalous acceleration has been one of the great problems in physics since…
This letter concentrates on the non-equilibrium evolution of magnetic field structures at the onset of recombination, when the charged particle current densities decay as neutrals are formed. We consider the effect that a decaying magnetic…
The notion of vacuum fluctuations of the gravitational field plays important role in cosmology. The strong variable gravitational field of the very early Universe amplifies these fluctuations and transforms them into macroscopical…
We show that short-range interactions between the fundamental particles in the universe can drive a period of accelerated expansion. This description fits the early universe. In the present day universe, if one postulates short-range…
The early Universe was characterized by the presence of heavy particles that decoupled at different temperatures leading to different phases of the Universe. This had a consequences on the time evolution of the thermodynamic and the…
RXTE, GINGA, and OSSE observations have revealed an intense low-energy gamma-ray continuum emission from the Galactic plane, which is commonly interpreted as evidence for the possible existence of a strong flux of low-energy cosmic ray…
Recently, it has been showed that a slow expansion, which is asymptotically a static state in infinite past and may be described as an evolution with \epsilon \ll -1, of early universe may lead to the generation of primordial perturbation…
The rate of terrestrial irradiation events by galactic gamma-ray bursts (GRBs) is estimated using recent standard-energy results. We assume that GRBs accelerate high-energy cosmic rays, and present results of three-dimensional simulations…
We propose that repeated photoexcitation/ionization of high Z atoms of highly relativistic flows by star light in dense stellar regions followed by emission of decay/recombination photons, which are beamed and boosted to gamma ray energies…
Nonlinear electron emission processes induced by surface plasmon oscillations have been studied both experimentally and theoretically. The measured above-threshold electron spectra extend up to energies whose appearance cannot be explained…
We consider energy deposition of high energy electrons and photons in universe. We carry out detailed calculations of fractions of the initial energy of the injected electron or photon which are used to heat, ionize and excite background…
In the present model, a unified picture of cosmology from early inflation to late acceleration is obtained from $ f(R)-$ gravity with non-linear terms $ R^2 $ and $ R^5 $ of scalar curvature $R$. It is discussed that elementary particles…
The universe is found to have undergone several phases in which the gravitational constant had different behaviors. During some epochs the energy density of the universe remained constant and the universe remained static. In the radiation…
We investigate the electromagnetic cascade initiated by injection of very high energy photons in the early Universe and calculate the cascade spectrum by solving a set of Boltzmann equations numerically. In the calculation we take account…
We present a quantum-field-theoretical study of bremsstrahlung from an electron propagating in a linearly polarized background photon field. Starting from the photon two-point correlator, the background-modified photon propagator is…
We propose a model for gamma ray bursts in which a star subject to a high level of fermion degeneracy undergoes a phase transition to a supersymmetric state. The burst is initiated by the transition of fermion pairs to sfermion pairs which,…
We investigate the cosmology of a recently proposed deformation of Einstein gravity, emerging from quantum gravity heuristics. The theory is constructed to have de Sitter space as a vacuum solution, and thus to be relevant to the…