Related papers: Spectrum of Background X-rays from Moduli Dark Mat…
We calculate, using unitarity, a lower bound on the branching ratio $\chi\chi\to \gamma\gamma$ and $\chi\chi\to \gamma Z$, where $\chi$ is any halo dark matter particle that has $W^+W^-$ as one of the major annihilation modes. Examples of…
We revisit the possibility of light scalar dark matter, in the MeV to GeV mass bracket and coupled to electrons through fermion or vector mediators, in light of significant experimental and observational advances that probe new physics…
We analyze the impact of future hard X-ray observations on the search for indirect signatures of particle dark matter in large extragalactic systems such as nearby clusters or groups of galaxies. We argue that the hard X-ray energy band…
If dark matter is unstable and the mass is within GeV-TeV regime, its decays produce high-energy photons that give contribution to the extragalactic gamma-ray background (EGRB). We constrain dark matter decay by analyzing the 50-month EGRB…
Lines in the spectrum of cosmic gamma rays are considered one of the more robust signatures of dark matter annihilation. We consider such processes from an effective field theory vantage, and find that generically, two or more lines are…
Decaying or annihilating dark matter particles could be detected through gamma-ray emission from the species they decay or annihilate into. This is usually done by modelling the flux from specific dark matter-rich objects such as the Milky…
We further study a scenario in which a 3.55 keV X-ray line arises from decay of dark matter to an axion-like particle (ALP), that subsequently converts to a photon in astrophysical magnetic fields. We perform numerical simulations of…
Precision measurements of the positron flux in cosmic ray have revealed an unexplained bump in the spectrum around $E\simeq 300\,\mathrm{GeV}$, not clearly attributable to known astrophysical processes. We propose annihilation of dark…
TeV-mass dark matter charged under a new GeV-scale gauge force can explain electronic cosmic-ray anomalies. We propose that the CoGeNT and DAMA direct detection experiments are observing scattering of light stable states -- "GeV-Matter" --…
Dark matter particles may decay, emitting photons. Drawing on the EAGLE family of hydrodynamic simulations of galaxy formation -- including the APOSTLE and C-EAGLE simulations -- we assess the systematic uncertainties and scatter on the…
The observation of cosmic sub-PeV gamma-rays from the Crab Nebula opens up the possibility of testing cosmic ray photon transparency at the multi-hundred TeV scale. Assuming no deviation from a source gamma-ray emission due to accelerated…
We analyze publicly available Fermi-LAT high-energy gamma-ray data and confirm the existence of clear spectral feature peaked at E=130GeV. Scanning over the Galaxy we identify several disconnected regions where the observed excess…
Clear methods to differentiate between decaying and annihilating dark matter (DM) scenarios are still by and large unavailable. In this note, we study the potential astrophysical signatures of a new class of hidden sector decaying DM…
MMonochromatic neutrinos from dark matter annihilations ($\chi\chi\to \nu\bar\nu$) are always produced in association with a gamma-ray spectrum generated by electroweak bremsstrahlung. Consequently, these neutrino lines can be searched for…
Galaxy clusters are promising targets for indirect dark matter searches. Gamma-ray signatures from the decay or annihilation of dark matter particles inside these clusters could be observable with the Fermi Large Area Telescope (LAT). Based…
We study the growth of density perturbations in a universe with unstable dark matter particles. The mass (m_\nu) range 30 eV < m_\nu < 10 keV with lifetimes ($t_d$) in the range 10^7 sec < t_d < 10^16 sec are considered. We calculate the…
We study the possibility to use line-intensity mapping (LIM) to seek photons from the radiative decay of neutrinos in the cosmic neutrino background. The Standard Model prediction for the rate for these decays is extremely small, but it can…
Dark matter decay or annihilation may produce monochromatic signals in the gamma-ray energy range. In this work we argue that there are strong theoretical motivations for studying these signals in the framework of gravitino dark matter…
The diffuse galactic EGRET gamma ray data show a clear excess for energies above 1 GeV in comparison with the expectations from conventional galactic models. The excess is seen with the same spectrum in all sky directions, as expected for…
"Dark Photons", light new vector particles V kinetically mixed with the photon, are a frequently considered extension of the Standard Model. For masses below 10 keV they are emitted from the solar interior. In the limit of small mass m_V…