Related papers: Synchrotron Radiation from the Galactic Center in …
Recent observations of a large excess of cosmic-ray positrons at high energies have raised a lot of interest in leptonic decay modes of dark matter particles. Nevertheless, dark matter particles in the Milky Way halo could also decay…
The synchrotron radiation emitted by runaway electrons in a fusion plasma provides information regarding the particle momenta and pitch-angles of the runaway electron population through the strong dependence of the synchrotron spectrum on…
Here we briefly review possible indirect effects of dark matter (DM) of the Universe. It includes effects in cosmic rays (CR): first of all, the positron excess at $\sim$ 500 GeV and possible electron-positron excess at 1-1.5 TeV. We tell…
Both radiative and mechanical feedback from Active Galactic Nuclei have been found to be important for the evolution of elliptical galaxies. We compute how a shock may be driven from a central black hole into the gaseous envelope of an…
In this work, we propose a novel mechanism for generating gamma rays from the Galactic Center via scattering of cosmic-ray protons off dark matter in the Milky Way halo, in contrast to conventional explanations based on dark matter…
Recent measurements of cosmic-ray electron and positron fluxes by PAMELA and ATIC experiments may indicate the existence of annihilating dark matter with large annihilation cross section. We discuss its possible relation to other…
The standard calculations of the synchrotron emission from charged particles in magnetic fields does not apply when the energy losses of the particles are so severe that their energy is appreciably degraded during one Larmor rotation. In…
Particle dark matter near the galactic center is accreted by the central black hole into a dense spike, strongly enhancing its annihilation rate. Searching for its annihilation products may give us information on the presence or absence of…
The high positron production rate required to explain the flux of 511 keV gamma rays from the galactic center has inspired many models in which dark matter creates positrons. These models include the annihilation of light dark matter and…
In light of recent observations of an anomalous excess of high-energy positrons and electrons by the PAMELA and Fermi LAT experiments, we investigate exotic cosmic-ray signatures in scenarios with unstable dark matter that decays with an…
Recent observations of the 511 keV positron-electron annihilation line in the Galactic centre region by the INTEGRAL/SPI spectrometer have stirred up new speculations about the origin of the large corresponding positron injection rate.…
We construct empirical models of the diffuse gamma-ray background toward the Galactic Center. Including all known point sources and a template of emission associated with interactions of cosmic rays with molecular gas, we show that the…
We study a scenario that a hidden gauge boson constitutes the dominant component of dark matter and decays into the standard model particles through a gauge kinetic mixing. Interestingly, gamma rays and positrons produced from the decay of…
About one year ago, it was speculated that decaying or annihilating Light Dark Matter (LDM) particles could explain the flux and extension of the 511 keV line emission in the galactic centre. Here we present a thorough comparison between…
The cosmic ray data of PAMELA/ATIC may be explained by dark matter decay with a decay rate $\tau_{DM}^{-1}\sim 10^{-26}{sec}^{-1} \sim 10^{-45}{eV}$, an energy scale which could not be understood within the framework of the standard model…
We present a supersymmetric model with two dark matter (DM) components explaining the galactic positron excess observed by PAMELA/HEAT and ATIC/PPB-BETS: One is the conventional (bino-like) lightest supersymmetric particle (LSP) \chi, and…
We consider a synchrotron radiation from a charged particle moving in a bound orbit around a weakly magnetized Schwarzschild black hole (a static black hole immersed into a constant uniform magnetic field) in its equatorial plane,…
Low-frequency radio emission from the Large Magellanic Cloud~(LMC) is assumed to be dominated by nonthermal synchrotron radiation from energy loss of energetic $e^+/e^-$ in magnetic field. Two different kinds of sources of $e^+/e^-$, dark…
Models for the diffuse Galactic continuum emission and synchrotron radiation show that it is difficult to reproduce observations of both of these from the same population of cosmic-ray electrons. This indicates that an important contributor…
The scenario of gravitino dark matter with broken R-parity naturally reconciles three paradigms that, albeit very well motivated separately, seem to be in mutual conflict: supersymmetric dark matter, thermal leptogenesis and standard Big…