相关论文: Neutral and Millicharged Dark Matter Decay into Ga…
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…
A monochromatic gamma ray line results when dark matter particles in the galactic halo annihilate to produce a two body final state which includes a photon. Such a signal is very distinctive from astrophysical backgrounds, and thus…
Most proposed dark matter candidates are stable and are produced thermally in the early Universe. However, there is also the possibility of unstable (but long-lived) dark matter, produced thermally or otherwise. We propose a strategy to…
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…
Determining the fundamental properties of the dark matter is one of the most important open problems in particle physics today. If the dark matter particle has spin zero, one of these properties is its CP nature. That is, whether it is…
We show that there exists only a quite limited number of higher dimensional operators which can naturally lead to a slow decay of dark matter particles into monochromatic photons. As each of these operators inevitably induces decays into…
The nature of dark matter is one of the most pressing questions in modern cosmology. Much work has been focussed in the past upon probing potential particle dark matter via gamma-rays resulting from its annihilation or decay. These processs…
Dark matter particle annihilation or decay can produce monochromatic gamma-ray lines and contribute to the diffuse gamma-ray background. Flux upper limits are presented for gamma-ray spectral lines from 7 to 200 GeV and for the diffuse…
Although most proposed dark matter candidates are stable, in order for dark matter to be present today, the only requirement is that its lifetime is longer than the age of the Universe, t_U ~ 4 10^17 s. Moreover, the dark matter particle…
We explore theories of dark matter in which dark matter annihilations produce mono-energetic gamma rays ("lines") in the context of effective field theory, which captures the physics for cases in which the particles mediating the…
Monochromatic gamma-rays are thought to be the smoking gun signal for identifying the dark matter annihilation. However, the flux of monochromatic gamma-rays is usually suppressed by the virtual quantum effects since dark matter should be…
A leading hypothesis for the nature of the elusive dark matter are thermally produced, weakly interacting massive particles that arise in many theories beyond the standard model of particle physics. Their self-annihilation in astrophysical…
In the energy range from few TeV to 25 TeV, upper bounds on the dark matter decay rate into high energy monochromatic neutrinos have recently become comparable to those on monochromatic gamma-ray lines. This implies clear possibilities of a…
High energy gamma-rays and neutrinos can be produced both by the annihilation and by the possible slow decay of dark matter particles. We discuss the fluxes and spectra of such secondaries produced by dark matter particles in the universe…
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…
A number of signals involving charged cosmic rays and high-energy photons have been interpreted as being due to annihilating dark matter. This article provides an overview of the experimental evidence and discusses in particular detections…
We study particle decay as the origin of dark radiation. After elaborating general properties and useful parametrisations we provide model-independent and easy-to-use constraints from nucleosynthesis, the cosmic microwave background and…
The decay of dark matter is predicted by many theoretical models and can produce observable contributions to the cosmic-ray fluxes. I shortly discuss the interpretation of the positron and electron excess as observed by PAMELA and Fermi LAT…
If dark matter particles have an electric charge, as in models of millicharged dark matter, such particles should be accelerated in the same astrophysical accelerators that produce ordinary cosmic rays, and their spectra should have a…
In this study, we present some general features of gamma-ray spectra from dark matter. We find that the spectrum with sharp features could appear in a wide class of dark matter models and mimic the gamma line signals. If all other physical…