Related papers: Leptogenesis and Gravitino Dark Matter
Gravitino problem is discussed in detail. We derive an upperbound on the reheating temperature from the constraints of the big-bang nucleosynthesis and the present mass density of the universe. Compared to previous works, we have improve…
The identification of dark matter in our particle physics model is still a very open question. Here we will argue that axinos can be successful dark matter candidates in models with supersymmetry and the axion solution of the strong CP…
If dark matter particles are not perfectly stable, their decay products might be seen in the cosmic-ray fluxes. A natural candidate for decaying dark matter is the gravitino in R-parity violating scenarios. In the relevant GeV-TeV energy…
Dark matter may be composed of superWIMPs, superweakly-interacting massive particles produced in the late decays of other particles. We focus on the case of gravitinos produced in the late decays of sleptons or sneutrinos and assume they…
In the framework of the scotogenic model, which features radiative generation of neutrino masses, we explore light dark matter scenario. Throughout the paper we chiefly focus on keV-scale dark matter which can be produced either via…
Weak scale supersymmetry is a highly motivated extension of the Standard Model that has a strong degree of support from data. It provides several viable dark matter candidates: the lightest neutralino (a WIMP), the gravitino, and the…
The origin of the hot phase of the early universe remains so far an unsolved puzzle. A viable option is entropy production through the decays of heavy Majorana neutrinos whose lifetimes determine the initial temperature. We show that…
I suggest a new extension of the SM by introducing a dark sector which has several new particles and a local $U(1)_{D}$ symmetry. The dark particles bring about the new and interesting physics beyond the SM. The model can generate the tiny…
Gravitinos are very promising candidates for the cold dark matter of the Universe. Interestingly, to achieve a sufficiently long gravitino lifetime, R-parity conservation is not required, thus preventing any dangerous cosmological influence…
We present a full one-loop calculation of the gravitino thermal production rate, beyond the so-called hard thermal loop approximation, using the corresponding thermal spectral functions in numerical form on both sides of the light cone.…
I report on some scenarios where the gravitino is the dark matter and the supersymmetry breaking mediated by a gauge sector.
We consider a model for a Z'-boson coupled only to baryon minus lepton number and hypercharge. Besides the usual right-handed neutrinos, we add a pair of fermions with a fractional lepton charge, which we therefore call leptinos. One of the…
Two leading dark matter candidates from supersymmetry and other theories of physics beyond the standard model are WIMPs and weak scale gravitinos. If the lightest stable particle is a gravitino, then a WIMP will decay into it with a natural…
We revisit Higgs inflation in the framework of a minimal extension of the Standard Model gauge symmetry by a $U(1)_{B-L}$ factor. Various aspects are taken into account with particular focus on the role of the supersymmetry breaking (SUSY)…
We examine resonant slepton production at the LHC with gravitinos in the final state. The slepton undergoes gauge decay into a neutralino and a lepton, the neutralino decays into a photon and a gravitino. By measuring the transverse masses…
Partial Split Supersymmetry with bilinear R-parity violation allows to reproduce all neutrino mass and mixing parameters. The viable dark matter candidate in this model is the gravitino. We study the hypothesis that both possibilities are…
An attractive way to generate neutrino masses as required to account for current neutrino oscillation data involves the spontaneous breaking of lepton number. The resulting majoron may pick up a mass due to gravity. If its mass lies in the…
At the end of inflation, the inflaton field decays into an initially nonthermal population of relativistic particles which eventually thermalize. We consider the production of dark matter from this relativistic plasma, focusing on the…
Gravitino production and decay in the inflationary universe are reexamined. Assuming that the gravitino mainly decays into a photon and a photino, we calculate the upperbound on the reheating temperature. Compared to previous works, we have…
We propose a new scenario of non-thermal production of neutralino cold dark matter, in which the overproduction problem of lightest supersymmetric particles (LSPs) in the standard thermal history is naturally solved. The mechanism requires…