arXiv subjects

L. Pizza

Publications and source records attributed to L. Pizza.

2 recordsLinked to original sources

arXiv2015

Cosmological evolution of thermal relic particles in $f(R)$ gravity

By considering $f(R)$ gravity models, the cosmic evolution is modified with respect to the standard $Λ$CDM scenario. In particular, the thermal history of particles results modified. In this paper, we derive the evolution of relics particles (WIMPs) assuming a reliable $f(R)$ cosmological solution and taking into account observational constraints. The connection to the PAMELA experiment is also discussed. Results are consistent with constraints coming from BICEP2 and PLANCK experiments.

astro-ph.CO↗

arXiv2012

Consequences of f(R)-theories of gravity on gravitational leptogenesis

f(R)-theories of gravity are reviewed in the framework of the matter-antimatter asymmetry in the Universe. The asymmetry is generated by the gravitational coupling of heavy (Majorana) neutrinos with the Ricci scalar curvature. In order that the mechanism works, a time varying non-zero Ricci curvature is necessary. The latter is provided by f(R) cosmology, whose Lagrangian density is of the form {\cal L}(R)\sim f(R). In particular we study the cases f(R)\sim R+αR^n and f(R)\sim R^{1+ε}.

hep-ph↗