Related papers: Coherent Smith-Purcell $\gamma$-Ray Emission
We describe a general method for modeling gamma-ray burst prompt emission. We find that for the burst to be produced via the synchrotron process unphysical conditions are required -- the distance of the source from the center of the…
We report the observation of an exotic radiation (unconventional Smith-Purcell radiation) from a one-dimensional photonic crystal. The physical origin of the exotic radiation is direct excitation of the photonic bands by an…
We have identified a mechanism of collective nuclear de-excitation in a Bose-Einstein condensate of $^{135}$Cs atoms in their isomeric states, $^{135m}$Cs, suitable for the generation of coherent gamma photons. The process described here…
The paper is devoted to the analysis of particle acceleration in Gamma-Ray Bursts and its radiative consequences. Therefore we get on one hand constraints on the physics and on the other hand possible signatures of particle acceleration…
Very hot plasmas with ion temperature exceeding $10^{10}$ K can be formed in certain astrophysical environments. The distinct radiation signature of such plasmas is the $\gamma$-ray emission dominated by the prompt de-excitation nuclear…
Fission and gamma-emission probabilities induced by transfer or inelastic scattering reactions with light projectile nuclei are very valuable quantities for constraining the models that describe the de-excitation of heavy nuclei. We have…
The Smith Purcell radiation as one promising THz radiation source has been studied for decades. Various structure designs and beam configurations have been proposed. In this paper, we report our recent exploration of Smith Purcell radiation…
We investigate spontaneous photon emission processes of two-level atoms in parabolic and ellipsoidal cavities thereby taking into account the full multimode scenario. In particular, we calculate the excitation probabilities of the atoms and…
The spontaneous emission of radiation of metallic electrons embedded in a high-intensity enhanced surface plasmon field is considered analytically. The electrons are described by exact dressed quantum states which contain the interaction…
The radiation of photons by electrons is investigated in the framework of quantum electrodynamics up to the second order in the coupling constant $e$. The $N$-particle, coherent, and thermal initial states are considered and the forms of…
Synchrotron radiation from accelerated electrons above the photosphere of a relativistic ejecta is a natural candidate for the dominant process for the prompt GRB emission. There is however a tension between the predicted low-energy…
In this paper we analyze the dynamics of single-excitation states, which model the scattering of a single photon from multiple two level atoms. For short times and weak atom-field couplings we show that the atomic amplitudes are given by a…
The new regime of resonant nuclear photoexcitation rendered possible by x-ray free electron laser beams interacting with solid state targets is investigated theoretically. Our results unexpectedly show that secondary processes coupling…
We investigate MeV-GeV $\gamma$-ray outbursts in 3C 273 in the frame of a time-dependent one-zone synchrotron self-Compton (SSC) model. In this model, electrons are accelerated to extra-relativistic energy through the stochastic particle…
We show here that the photonic states emitted by ensembles of multilevel atoms via a superradiance process exhibit entanglement in the modal (frequency) degree of freedom, making this collective emission process a favorable candidate for a…
Gamma-ray bursts (GRBs) are highly variable and exhibit strong spectral evolution. In particular, the emission properties vary from pulse to pulse in multipulse bursts. Here we present a time-resolved Bayesian spectral analysis of a…
Unsteady activity of gamma-ray burst sources leads to internal shocks in their emergent relativistic wind. We study the emission spectra from such shocks, assuming that they produce a power-law distribution of relativistic electrons and…
We study Smith-Purcell radiation from a conducting grating generated by an inclined passage of a shaped electron wave packet with an electric quadrupole moment in the non-paraxial regime. Spreading of an asymmetric wave packet induces…
Detailed information on the physical parameters in the sources of cosmological Gamma-Ray Bursts (GRBs) is obtained from few plausible assumptions consistent with observations. Model-independent requirements posed by these assumptions on the…
We develop a model for a possible origin of hard very high energy spectra from a distant blazar. In the model, both the primary photons produced in the source and secondary photons produced outside the source contribute to the observed high…