Related papers: Unstable Gravitino Dark Matter and Neutrino Flux
We consider the possibility that supersymmetry is broken above the inflationary mass scale and that the only "low" energy remnant of supersymmetry is the gravitino with mass of order the EeV scale. The gravitino in this class of models…
Affleck-Dine baryogenesis, accompanied by the formation and subsequent decay of Q-balls, can generate both the baryon asymmetry of the universe and dark matter in the form of gravitinos. The gravitinos from Q-ball decay dominate over the…
In this paper we study the interplay between the recently proposed F-theory GUTs and cosmology. Despite the fact that the parameter range for F-theory GUT models is very narrow, we find that F-theory GUTs beautifully satisfy most…
A decay of the gravitino dark matter is an attractive candidate to explain the current excesses of the PAMELA/ATIC cosmic-ray data. However, R-parity violations are required to be very tiny in low-energy scale. We suggest a R-parity…
We have considered nonuniversal gaugino mass models of supergravity, arising from a mixture of two superfield contributions to the gauge kinetic term, belonging to a singlet and a nonsinglet representation of the GUT group. In particular we…
We analyze scenarios in which some flavour of sneutrino is the next-to-lightest supersymmetric particle (NLSP), assuming that the gravitino is the lightest supersymmetric particle (LSP) and provides the cold dark matter. Such scenarios do…
In the framework of the Constrained MSSM we re--examine the gravitino as the lightest superpartner and a candidate for cold dark matter in the Universe. Unlike in other recent studies, we include both a thermal contribution to its relic…
We present a new scenario of gravitino dark matter which is compatible with the thermal leptogenesis. We confirm by an explicit calculation in supergravity that the relic abundance of thermally produced gravitino becomes insensitive to the…
The standard model (SM) of particle physics is for the last three decades a very successful description of the properties and interactions of all known elementary particles. Currently, it is again probed with the first collisions at the…
A striking aspect of the recently proposed split supersymmetry is the existence of heavy gluinos which are metastable because of the very heavy squarks which mediate their decay. In this paper we correlate the expected flux of these…
I address the question of whether supersymmetry provides a viable candidate for the dark matter in the Universe. I review the properties of the lightest neutralino as a candidate for solving the dark matter problem. I discuss the…
If a bosonic partner of a right-handed neutrino dominates the early universe sufficiently before its decay, important ingredients in the present universe are related to physics of the right-handed neutrino sector. In particular, we find…
The observation of very high energy neutrino events at IceCube has grasped a lot of attention in the fields of both astrophysics and particle physics. It has been speculated that these high energy neutrinos might originate either from…
We discuss the prospects for detection of high energy neutrinos from dark matter annihilation at the Galactic centre. Despite the large uncertainties associated with our poor knowledge of the distribution of dark matter in the innermost…
We derive big-bang nucleosynthesis (BBN) constraints on both unstable and stable gravitino taking account of recent progresses in theoretical study of the BBN processes as well as observations of primordial light-element abundances. In the…
In the recently proposed `split supersymmetry' scenario, the squark and slepton masses are allowed to be at a high scale while the gauginos and Higgsinos are within a TeV. We show that in a theory with broken R-parity, the parameter space…
We study the phase transition of a system of self-gravitating neutrinos in the presence of a large radiation density background in the framework of the Thomas-Fermi model. We show that, by cooling a non-degenerate gas of massive neutrinos…
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…
Gamma-ray bursts (GRBs) are expected to provide a source of ultra high energy cosmic rays, accompanied with potentially detectable neutrinos at neutrino telescopes. Recently, IceCube has set an upper bound on this neutrino flux well below…
Non-universal boundary conditions in grand unified theories can lead to non-universal gaugino masses at the unification scale. In R-parity preserving theories the lightest supersymmetric particle is a natural candidate for the dark matter.…