Sharp spectral features from light dark matter decay via gravity portals

Antideuterons from Dark Matter Decay

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 hadronically, producing not only a flux of antiprotons but also a flux of antideuterons. We show that for certain choices of parameters the antideuteron flux from ...

Cosmic Rays from Leptophilic Dark Matter Decay via Kinetic Mixing

If interpreted in terms of decaying dark matter, the steep rise in the positron fraction of cosmic rays above 10GeV, as observed by the PAMELA experiment, suggests an underlying production mechanism that favors leptonic channels. We consider a scenario where a portion of the dark matter is made of the gauginos of an unbroken hidden-sector U(1)X , which interact with the visible sector only thro...

Bright Light from Dark Matter

Neutralino dark matter from heavy axino decay

Ki-Young Choi, 2, ∗ Jihn E. Kim, † Hyun Min Lee, ‡ and Osamu Seto § Departamento de F́ısica Teórica C-XI, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain Instituto de F́ısica Teórica UAM/CSIC, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain 3 Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea Department of Physics, Carnegie Mello...

Artifact Dark Matter from Unified Brane Gravity

Adopting Dirac’s brane variation prescription, the energy-momentum tensor of a brane gets supplemented by a geometrical (embedding originated) dark component. While the masslessness of the graviton is preserved, and the Newton force law is recovered, the corresponding Newton constant is necessarily lower than the one which governs FRW cosmology. This has the potential to puzzle out cosmological...