Related papers: Cosmology of F-theory GUTs
We revisit the gravitational leptogenesis scenario in which the inflaton is coupled to gravity by the Chern-Simons term and the lepton asymmetry is generated through the gravitational anomaly in the lepton number current during inflation.…
We implement the asymmetric dark matter framework, linking the ordinary and dark matter abundances, within a supersymmetric context. We consider a supersymmetric model that respects an approximate $U(1)_R$ symmetry, which is broken in such…
Cosmological evolution and particle creation in $R^2$-modified gravity are considered for the case of the dominant decay of the scalaron into a pair of gauge bosons due to conformal anomaly. It is shown that in the process of thermalization…
We consider realizations of GUT models in F-theory. Adopting a bottom up approach, the assumption that the dynamics of the GUT model can in principle decouple from Planck scale physics leads to a surprisingly predictive framework. An…
Recent studies of the cosmic microwave background, large scale structure, and big bang nucleosynthesis (BBN) show trends towards extra radiation. Within the framework of supersymmetric hadronic axion models, we explore two…
Scenarios with gravitino dark matter face potential cosmological problems induced by the presence of the Next-to-Lightest Supersymmetric Particle (NLSP) at the time of Big Bang Nucleosynthesis (BBN). A very simple, albeit radical, solution…
The production and the final abundance of gravitino dark matter appear to depend crucially on the restoration of the global U(1) $R$-symmetry of GMSB sectors in a threefold way. An $R$-symmetric phase effectively suppresses the production…
We consider the abundance of gravitinos created from the vacuum fluctuation, in a class of `new' inflation models for which global supersymmetry is a good approximation. Immediately after inflation, gravitinos are produced, with number…
The `$\mu$ from $\nu$' supersymmetric standard model ($\mu\nu$SSM) solves the $\mu$ problem of supersymmetric models and reproduces neutrino data, simply using couplings with the three families of right-handed neutrinos $\nu$'s. Novel…
We propose a predictive $SO(10)$ Grand Unified Theory (GUT) framework for cosmic inflation in the Palatini $\mathcal{R}^2$ formulation of gravity. In this model, a GUT Higgs field both drives inflation and induces intermediate-scale…
Dark matter (DM), in spite of being stable or long-lived on cosmological scales, can decay in the early Universe due to finite-temperature effects. In particular, a first order phase transition (FOPT) in the early Universe can provide a…
The viability of a possible cosmological scenario is investigated. The theoretical framework is the constrained next-to-minimal supersymmetric standard model (cNMSSM), with a gravitino playing the role of the lightest supersymmetric…
In higher-dimensional supersymmetric theories gauge couplings of the effective four-dimensional theory are determined by expectation values of scalar fields. We find that at temperatures above a critical temperature $T_*$, which depends on…
We calculate the relic abundance of mixed axion/neutralino cold dark matter which arises in R-parity conserving supersymmetric (SUSY) models wherein the strong CP problem is solved by the Peccei-Quinn (PQ) mechanism with a concommitant…
Asymmetric symmetry breaking models dynamically break the G X G gauge symmetries of mirror models to distinct subgroups in the two sectors. The coincidental abundances of visible and dark matter, $\Omega_{DM} \simeq 5\Omega_{VM}$, motivates…
A review is given on the consistency checks of GUT, which unify the electroweak and strong nuclear forces into a single theory. Such theories predict a new kind of force, which could provide answers to several open questions in cosmology.…
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.…
The supersymmetric SO(10) GUT based on the ${\bf{210\oplus 10\oplus 120\oplus 126\oplus {\bar {126}}}}$ Higgs system provides a minimal framework for the emergence of the R-parity exact MSSM at low energies and a viable supersymmetric…
If the gravitino is sufficiently light and stable it will behave as an effective massless neutrino species at the time of nucleosynthesis. Depending on the temperature at which it decouples from the thermal bath in the early universe, the…
We propose a simple grand unified theory (GUT) scenario in which supersymmetry (SUSY) is spontaneously broken in visible sector. Our model is based on the GUT model that has been proposed to solve almost all problems in conventional GUT…