PeV IceCube signals and Dark Matter relic abundance in modified cosmologies

Abstract

The discovery by the IceCube experiment of a high-energy astrophysical neutrino flux with energies of the order of PeV, has opened new scenarios in astroparticles physics. A possibility to explain this phenomenon is to consider the minimal models of Dark Matter (DM) decay, the 4-dimensional operator ∼ y αχ L L α H χ , which is also able to generate the correct abundance of DM in the Universe. Assuming that the cosmological background evolves according to the standard cosmological model, it follows that the rate of DM decay χ ∼ |y αχ | 2 needed to get the correct DM relic abundance ( χ ∼ 10 −58 ) differs by many orders of magnitude with respect that one needed to explain the IceCube data ( χ ∼ 10 −25 ), making the four-dimensional operator unsuitable. In this paper we show that assuming that the early Universe evolution is governed by a modified cosmology, the discrepancy between the two the DM decay rates can be reconciled, and both the IceCube neutrino rate and relic density can be explained in a minimal model.

Consequences of Modified Cosmologies in DM abundance and PeV IceCube signals

“…where H is the expansion rate of the Universe and C the general collision term. In modified cosmology, the DM relic abundance is given by [9] Ω DM h 2 0.1188 α |y αχ | 2 7.5 × 10 −24 Π , where Π ≡…”

“…where f (T ) = β T |T | n T (f (T ) is a generic function of the torsion T ). In such a case [9], one gets (see Eq. ( 1))…”

Photon frequency shift in curvature-based Extended Theories of Gravity

“…The weak-field limit has to be tested against realistic self-gravitating systems. Galactic rotation curves, stellar systems and gravitational lensing appear natural candidates as test-bed experiments [27][28][29][30][31][32] (see also [33][34][35]). In this perspective, corrections to GR were already considered by several authors [22,.…”

Virial theorem in scalar tensor fourth order gravity

“…Gravitational lensing, stellar hydrodynamics and Galactic rotation curves appear natural candidates as test-bed experiments [26][27][28][29][30][31]. In this field we have several contributions from various authors [32][33][34][35][36][37][38][39][40][41][42][43][44]. An interesting application concerns the study of the Casimir effect [45][46][47] in weak-field limit in the context of STFOG.…”