Related papers: Probing the Reheating Temperature at Colliders and…
The temperature of sphaleron freeze-out, $T\approx 130$ GeV, sets a scale for mechanisms for generating lepton asymmetries and converting them to baryon asymmetry (leptogenesis). For Majorana masses $M \gg \pi T$, leptogenesis takes place…
In this paper we study the reheating constraints on inflationary models considering perturbatively decaying inflaton. Important difference with the existing analysis is the inclusion of explicit decaying dynamics of inflaton during…
In many models of inflation, reheating is realized through a coupling between the inflaton and the Higgs boson. Often, the mass of the inflaton is of order $10^{13}~$GeV determined by the amplitude of the scalar fluctuation spectrum.…
Modifications to the Friedmann equation in brane cosmology can have important implications for early universe phenomena such as inflation and the generation of the baryon asymmetry. We study a simple scenario of chaotic brane inflation…
High-scale supersymmetry (SUSY) with a split spectrum has become increasingly interesting given the current experimental results. A SUSY scale above the weak scale could be naturally associated with a heavy unstable gravitino, whose decays…
We consider the collider phenomenology of split-supersymmetry models. We show that despite the challenging nature of the signals in these models the long-lived gluino can be discovered with masses in excess of 2 TeV at the LHC. At a future…
Gravitino produced in the inflationary universe are studied. When the gravitino decays into a neutrino and a sneutrino, the emitted high energy neutrinos scatter off the background neutrinos and produce charged leptons (mainly electrons and…
By using a No-Scale Supergravity model, which was proved to explain WMAP observations appropriately, a mechanism of supersymmetry breaking and a preheating just after the end of inflation are investigated. Non-thermal production rate of…
We point out that there is no cosmological gravitino problem in a certain class of gauge-mediated supersymmetry-breaking (GMSB) models. The constant term in the superpotential naturally causes small mixings between the standard-model and…
Motivated by our earlier paper \cite{am}, we discuss how the infamous gravitino problem has a natural built in solution within supersymmetry. Supersymmetry allows a large number of flat directions made up of {\it gauge invariant}…
We study the phenomenology of the CMSSM/mSUGRA with non-thermal neutralino dark matter. Besides the standard parameters of the CMSSM we include the reheating temperature as an extra parameter. Imposing radiative electroweak symmetry…
We propose an idea to build a bridge between reheating and late-time observations in quintessential inflation by backtracking the evolution of the inflaton field from the present time to the end of reheating. This idea is implemented when…
Searches for heavy long-lived charged particles are performed using a data sample of 19.8 fb$^{-1}$ from proton-proton collisions at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV collected by the ATLAS detector at the Large Hadron Collider.…
Recent developments in thermal leptogenesis are reviewed. Neutrino mixing data favor a simple picture where the matter-anti matter asymmetry is generated by the decays of the heavy RH neutrinos mildly close to thermal equilibrium and,…
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 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…
A feasibility study is presented to precisely measure the masses of charged sleptons and the lightest neutralino in $e^+e^-\to\smur\smur$ and $e^+e^-\to\stau_1\stau_1$ production. Different mSUGRA scenarios with small slepton-neutralino…
Since the thermal history of the Universe is unknown before the epoch of primordial nucleosynthesis, the largest temperature of the radiation dominated phase (the reheating temperature) might have been as low as 1 MeV. We perform a…
The gravitino problem gives a severe constraint on the thermal leptogenesis scenario. This problem leads us to consider some alternatives to it if we try to keep the gravitino mass around the weak scale $m_{3/2} \sim 100$ GeV. We consider,…
We revisit gravitino production following inflation. As a first step, we review the standard calculation of gravitino production in the thermal plasma formed at the end of post-inflationary reheating when the inflaton has completely…