Related papers: Implications of automatic photon quenching on comp…
Effective photon-photon luminosities are calculated for various realistic hadron collider scenarios. The main characteristics of photon-photon processes at relativistic heavy-ion colliders are established and compared to the corresponding…
There is a robust upper limit on the energy of synchrotron radiation in high-energy astrophysics: $ \sim m_{\rm e} c^2 /\alpha$, where $\alpha = 1/137$ is the fine structure constant and the value refers to the comoving frame of the fluid.…
Proposed dark matter detectors with eV-scale sensitivities will detect a large background of atomic (nuclear) recoils from coherent photon scattering. This background climbs steeply below $\sim10$~eVnr, far exceeding the declining rate of…
We make a new estimate of the extragalactic radio background down to kHz frequencies based on the observed luminosity functions and radio spectra of normal galaxies and radio galaxies. We have constructed models for the spectra of these two…
We observe that the pattern of the quenching factors for scintillation light from various ions, recently studied in $CaWO_4$ in connection with dark matter detectors, can be understood as a saturation phenomenon in which the light output is…
Ultrahigh-energy gamma rays ($E_{\gamma}>100 \, {\rm TeV}$) have been detected from a handful of astrophysical sources. Due to the Klein-Nishina suppression of inverse Compton scattering at such high energies, it has sometimes been argued…
The first published Fermi large area telescope (Fermi-LAT) measurement of the isotropic diffuse gamma-ray emission is in good agreement with a single power law, and is not showing any signature of a dominant contribution from dark matter…
Axionlike particles (ALPs) could mix with photons in the presence of astrophysical magnetic fields. Searching for this effect in gamma-ray observations of blazars has provided some of the strongest constraints on ALP parameter space so far.…
The low-energy monochromatic neutron emission from an Y-88/Be source can be exploited to mimic the few keVnr nuclear recoils expected from low-mass Weakly Interacting Massive Particles (WIMPs) and coherent scattering of neutrinos off…
The influence of the damping of radiation on the radiative energy loss spectrum of a relativistic charge in an infinite, absorptive plasma is studied. We find increasing reduction of the spectrum with increasing damping. Our studies, which…
This paper explores the effects of strong magnetic fields on the Compton scattering of relativistic electrons. Recent studies of upscattering and energy loss by relativistic electrons that have used the non-relativistic, magnetic Thomson…
The ultralight dark photon is a well-motivated, hypothetical dark matter candidate. In a dilute plasma, they can resonantly convert into photons, and heat up the intergalactic medium between galaxies. In this work, we explore the dark…
Photon-photon scattering at the Photon Linear Collider is considered. Explicit formulas for helicity amplitudes due to $W$ boson loops are presented. It is shown that photon-photon scattering should be easily observable at PLC and…
In this paper we consider photon-photon scattering due to self-induced gravitational perturbations on a Minkowski background. We focus on four-wave interaction between plane waves with weakly space and time dependent amplitudes, since…
Liquid-metal jet X-ray sources promise to deliver high photon fluxes, which are unprecedented for laboratory based X-ray sources, because the regenerating liquid-metal anode is less sensitive to damage caused by an increased electron beam…
Cosmic ray protons generate gamma-rays, neutrinos, and secondary electrons and positrons (e+/-) through pion-producing collisions with gas atoms. Any synchrotron or Inverse Compton (IC) radiation from secondary e+/- is therefore accompanied…
We employ an $^{88}$Y/Be photoneutron source to derive the quenching factor for neutron-induced nuclear recoils in germanium, probing recoil energies from a few hundred eV$_{nr}$ to 8.5keV$_{nr}$. A comprehensive Monte Carlo simulation of…
If a gamma-ray line is observed in the near future, it will be important to determine what kind of dark matter (DM) particle could be at its origin. We investigate the possibility that the gamma-ray line would be induced by a slow DM…
The decay of dark matter particles which are coupled predominantly to charged leptons has been proposed as a possible origin of excess high-energy positrons and electrons observed by cosmic-ray telescopes PAMELA and Fermi LAT. Even though…
We study the effect of stimulated photon emission from the vacuum in strong space-time-dependent electromagnetic fields. We emphasize the viewpoint that the vacuum subjected to macroscopic electromagnetic fields with at least one nonzero…