Related papers: Gravitinos from Heavy Scalar Decay
The cosmological moduli problem for relatively heavy moduli fields is reinvestigated. For this purpose we examine the decay of a modulus field at a quantitative level. The modulus dominantly decays into gauge bosons and gauginos, provided…
We derive cosmological constraints on the masses of generic scalar fields which decay only through gravitationally suppressed interactions into unstable gravitinos and ordinary particles in the supersymmetric standard model. For the…
One proposed solution of the moduli problem of string cosmology requires that the moduli are quite heavy, their decays reheating the universe to temperatures above the scale of nucleosynthesis. In many of these scenarios, the moduli are…
Gravitino production in the primordial Universe is investigated into details. After briefly reviewing inflation, supersymmetry and supergravity, we first study the scattering of massive W bosons in the thermal bath of particles, during the…
We study the cosmological consequences of generic scalar fields like moduli which decay only through gravitationally suppressed interactions. We consider a new production mechanism of gravitinos from moduli decay, which might be more…
Gravitinos are generically produced by inflaton decays, which place tight constraints on inflation models as well as supersymmetry breaking scale. We revisit the gravitino production from decays of the inflaton and the supersymmetry…
We show that gravitinos produced by decays of a supersymmetry breaking scalar field (the pseudo-moduli field) can naturally explain the observed abundance of dark matter in a certain class of the gauge mediation models. We study the decay…
Most of the inflation models end up with non-vanishing vacuum expectation values of the inflaton fields \phi in the true vacuum, which induce, in general, nonvanishing auxiliary field G_\phi for the inflaton potential in supergravity. We…
Scalar decay into gravitinos is studied in the presence of D-term supersymmetry (SUSY) breaking. The gravitinos produced by the decay of coherent oscillations of scalar fields, such as moduli and inflatons, cause cosmological problems. We…
We investigate the cosmological gravitino problem in gauge-mediated supersymmetry breaking models, where the gravitino becomes in general the lightest supersymmetric particle (LSP). In order to avoid the overclosure of the stable gravitino,…
A heavy scalar field such as moduli or an inflaton generally mixes with a field responsible for the supersymmetry breaking. We study the scalar decay into the standard model particles and their superpartners, gravitinos, and the…
We show that the gravitino-overproduction problem is prevalent among inflation models in supergravity. An inflaton field \phi generically acquires (effective) non-vanishing auxiliary field G_\phi, if the K\"ahler potential is non-minimal.…
Gravitino production and decay in the inflationary universe are reexanimed. Assuming that gravitino mainly decays into photon and photino, we have calculated the upperbound of the reheating temperature. Compared to previous works, we have…
We have recently shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in 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…
In supersymmetric models of warm inflation, the large temperature of the radiation bath produced by the dissipative motion of the inflaton field may induce a significant thermal abundance of potentially dangerous gravitinos. While previous…
The gravitino may well play an important role in cosmology, not only because its interactions are Planck-suppressed and therefore long-lived, but also because it is copiously produced via various processes such as particle scatterings in…
In supersymmetric theories, the gravitino is abundantly produced in the early Universe from thermal scattering, resulting in a strong upper bound on the reheat temperature after inflation. We point out that the gravitino problem may be…
Present data require a spectral index $n\gsim 0.95$ at something like 1-$\sigma$ level. If this lower bound survives it will constrain `new' and `modular' inflation models, while raising it to 1.00 would rule out all of these models plus…
We study the effects of the unstable gravitino on the big-bang nucleosynthesis. If the gravitino mass is smaller than \sim 10 TeV, primordial gravitinos produced after the inflation are likely to decay after the big-bang nucleosynthesis…