Related papers: Is Strong Gravitational Radiation predicted by TeV…
The recent detection of TeV gamma-radiation from the direction of the Galactic Center within several arc-minutes around Sgr A* is the first model-independent evidence of existence of high energy particle accelerator(s) in the central 10 pc…
An intergalactic magnetic field stronger than $3\times10^{-13}$~G would explain the lack of a bright, extended degree-scale, GeV-energy inverse Compton component in the gamma-ray spectra of TeV-blazars. A robustly predicted consequence of…
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 mere principle of relativity and Lorentz transformations for the mass current predict, in close analogy to electromagnetism, the existence of gravitomagnetic fields. With the reasonable assumption of the non existence of a…
The radio galaxy M87 has recently been found to be a rapidly variable TeV emitting source. We analyze the implications of the observed TeV characteristics and show that it proves challenging to account for them within conventional…
We consider heavy stable neutral particles in the context of supergravity and show that a gravitationally suppressed inflaton decay can produce such particles in cosmologically interesting abundances within a wide mass range $10^3 {\rm GeV}…
Recently it has been pointed out that the characteristic quantum-gravity scale could be as low as the weak scale in theories with gravity propagating in higher dimensions. The observed smallness of Newton's constant is a consequence of the…
Protons can be plausibly accelerated to $\sim 10^{18}$-$10^{19}$ eV in strong accretion shocks surrounding massive clusters of galaxies. Such protons efficiently produce very high energy pairs through interactions with the CMB, which then…
The recent detection of gamma radiation from Mkn 501 at energies as high as 25 TeV suggests stringent upper bounds on the diffuse, far infrared, extragalactic radiation density. The production of electron-positron pairs through…
Synchrotron radiation has markedly different behavior in $\sim 10~\textrm{keV}$ and in $\sim 100~\textrm{keV}$ plasma. We show that high-energy electrons which occupy the tail of velocity distribution function have disproportionate impact…
Cosmic topological defects in a wide class of supersymmetric theories can simultaneously be sources of higgs particles of mass comparable to the supersymmetry breaking scale $\sim$ TeV, as well as superheavy gauge bosons of mass $\sim\eta$,…
If the Planck scale is near a TeV, black hole production should be possible at colliders, as well as by cosmic rays. I begin with a review of the two approaches to TeV-scale gravity, large extra dimensions and warped compactification,…
It has been shown recently that within the framework of the teleparallel equivalent of general relativity (TEGR) it is possible to define the energy density of the gravitational field. The TEGR amounts to an alternative formulation of…
We study quantum-gravitational signatures at the Large Hadron Collider (LHC) in the context of theories with extra spatial dimensions and a low fundamental Planck scale in the TeV range. Implications of a gravitational fixed point at high…
Broadband spectral energy distributions (SEDs) are complied from literature for 24 TeV BL Lac objects. Two SEDs, which are identified as low and high states with their flux densities at $1\ {\rm TeV}$ ($F_{1 TeV}$), are available for each…
It is generally held that >100 TeV emission from astrophysical objects unambiguously demonstrates the presence of PeV protons or nuclei, due to the unavoidable Klein-Nishina suppression of inverse Compton emission from electrons. However,…
We study the synchrotron radiation of gluons by fast quarks in strong magnetic field produced by colliding relativistic heavy-ions. We argue that due to high electric conductivity of plasma, time variation of the magnetic field is slow and…
Long-duration GRBs are the most luminous sources of electromagnetic radiation known in the Universe. Their initial prompt flashes of MeV gamma rays are followed by longer-lasting afterglow emission from radio waves to GeV gamma rays.…
Supernova 1006 is the first shell type supernova remnant to show evidence of particle acceleration to TeV energies. In the present paper we examine this possibility by modeling the observed X-ray non-thermal emission in terms of synchrotron…
We analyze LHC data in order to constrain the parameter space of new spin-2 particles universally coupled to the energy-momentum tensor. These new hypothetical particles are the so-called hidden gravitons, whose phenomenology at low…