Related papers: Testing Relativity at High Energies Using Spacebor…
The components of blazar jets that emit radiation span a factor of $10^{10}$ in scale. The spatial structure of these emitting regions depends on the observed energy. Photons emitted at different sites cross the lens plane at different…
A polarized gamma ray emission spread over a sufficiently wide energy band from a strongly magnetized astrophysical object like gamma ray bursts (GRBs) offers an opportunity to test the hypothesis of axion like particles (ALPs). Based on…
We consider the ensemble of very-high-energy gamma-ray sources observed at distances and energies where a significant absorption of gamma rays is expected due to pair production on the extragalactic background light (EBL). Previous studies…
The Earth's high energy gamma-ray emission is caused by cosmic ray interactions with the atmosphere. The EGRET detector on-board the CGRO satellite is only the second experiment (after SAS-2) to provide a suitable dataset for the…
Gamma rays from TeV blazars have been detected by ground-based experiments for more than two decades. We have collected the most extensive set of archival spectra from these sources in order to constrain the processes affecting gamma-ray…
Lorentz invariance is such an important principle of fundamental physics that it should constantly be subjected to experimental scrutiny as well as theoretical questioning. Distant astrophysical sources of energetic photons with rapid time…
Context. Gamma-ray bursts (GRBs) can be detected at cosmological distances and therefore can be used to study the contents and phases of the early Universe. The 4-150 keV wide-field trigger camera ECLAIRs to fly on board the Space-based…
Low-frequency gravitational-wave astronomy can perform precision tests of general relativity and probe fundamental physics in a regime previously inaccessible. A space-based detector will be a formidable tool to explore gravity's role in…
Astrophysical scenarios provide a unique opportunity to test the possible signatures of Lorentz Invariance Violation (LIV) due to the high energies and the very long distances they involve. An isotropic correction to the photon dispersion…
The site and mechanism of gamma-ray burst (GRB) prompt emission is still unknown. Although internal shocks have been widely discussed as the emission site of GRBs, evidence supporting other emission sites have been also suggested recently,…
The observation of Gamma Ray Bursts (GRBs) with very-high-energy (VHE) gamma rays can provide understanding of the particle acceleration mechanisms in GRBs, and can also be used to probe the extra-galactic background light and place…
We report on VERITAS observations at energies above 200 GeV of known or potential galactic gamma-ray sources. The observed objects comprise pulsars, pulsar wind nebulae, high-mass X-ray binaries and gamma-ray sources with unknown…
We consider the observation of stellar-mass black holes binaries with the Laser Interferometer Space Antenna (LISA). Preliminary results based on Fisher information matrix analyses have suggested that gravitational waves from those sources…
The Lorentz invariance violation (LIV) predicted by some quantum gravity theories would manifest as an energy-dependent speed of light, which may potentially distort the observed temporal profile of photons from astrophysical sources at…
Violations of Lorentz Invariance, a cornerstone of modern physics, are predicted by theories of quantum gravity and by extensions of General Relativity involving new vector or tensor fields. In the weak-field limit, such a violation would…
The influence of intergalactic magnetic fields on the strong gravitational lensing of blazar secondary gamma radiation is discussed. Currently, two cases of strong gravitational lensing of blazar gamma-radiation are known, where radiation…
A brief review of the indirect detection signatures of dark matter is given. In particular, detection methods of dark matter particle annihilation to antimatter and gamma-rays are reviewed. With the GLAST satellite soon to be launched, a…
The inner regions of active galaxies host the most extreme and energetic phenomena in the universe including, relativistic jets, supermassive black hole binaries, and recoiling supermassive black holes. However, many of these sources cannot…
Blazars are highly variable sources over timescales that can be as low as minutes. This is the case of the High Energy Peaked BL Lac (HBL) objects showing strong variability in X-rays, which highly correlate with that of the TeV emission.…
Since mid-2007 we have carried out a dedicated long-term monitoring programme at 15 GHz using the Owens Valley Radio Observatory 40 meter telescope. One of the main goals of this programme is to study the relation between the radio and…