Related papers: The Moduli and Gravitino (non)-Problems in Models …
Even with recent progress, it is still very much an open question to understand how all compactification moduli are stabilized, since there are several mechanisms. For example, it is possible to generate a scalar potential either…
Gravitinos are expected to be produced in any local supersymmetric model. Using their abundance prediction as a function of the reheating energy scale, it is argued that the next generation of Cosmic Microwave Background experiments could…
We study the neutralino decay in the supersymmetric extra U(1) models which can solve the $\mu$-problem. In these models the neutralino sector is extended at least into six components by an extra U(1) gaugino and a superpartner of a singlet…
We estimate the abundance of the coherent oscillation of moduli, which linearly couple to matter fields through higher dimensional operators. During the (p)reheating after inflation, matter particles are efficiently produced and it can…
Many models of supersymmetry breaking, in the context of either supergravity or superstring theories, predict the presence of particles with weak scale masses and Planck-suppressed couplings. Typical examples are the scalar moduli and the…
We examine stabilities of our supersymmetry-breaking false vacuum in a low-energy direct gauge mediation model of SUSY breaking. The stability required in the high-temperature early universe leads to upperbounds on masses of squarks and…
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,…
We study models of gauge-mediated supersymmetry breaking with messengers that do not belong to complete representations of grand-unified gauge groups. We show that certain setups characterized by heavy Wino can greatly improve the fine…
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…
The success of primordial nucleosynthesis imposes stringent bounds on the abundance of gravitational relics. This is particularly true for gravitinos, which - for models with gravitationally mediated supersymmetry breaking - are expected to…
In this paper, we explore the parameter space of hilltop supernatural inflation model and show the regime within which there is no gravitino problem even if we consider both thermal and nonthermal production mechanisms. We make plots for…
It is shown how metastable de Sitter vacua might arise from heterotic M-theory. The balancing of its two non-perturbative effects, open membrane instantons against gaugino condensation on the hidden boundary, which act with opposing forces…
We study the problem of moduli stabilisation in explicit heterotic orbifold compactifications, whose spectra contain the MSSM plus some vector-like exotics that can be decoupled. Considering all the bulk moduli, we obtain the 4D low energy…
In this letter we demonstrate the genericity of suppressed gaugino masses M_a \sim m_{3/2}/ln(M_P/m_{3/2}) in the IIB string landscape, by showing that this relation holds for D7-brane gauginos whenever the associated modulus is stabilised…
In recent work, it has been argued that multi-TeV masses for scalar superpartners are not unnatural. Indeed, they appear to have significant phenomenological virtues. Here we explore the implications of such `focus point' supersymmetry for…
In string/M-theory with a large compactification radius, some axion-like moduli can be much lighter than the gravitino. Generic moduli in gauge-mediated supersymmetry breaking models also have a mass far below the weak scale. Motivated by…
Light moduli fields, gravitationally coupled scalar fields with no classical potential and which are expected to emerge as remnants from string theory compactification, are dangerous to cosmology in that 1. their late-time decays may…
We review moduli stabilization in type IIB string theory compactification with fluxes. We focus on the KKLT and Large Volume Scenario (LVS). We show that the predicted soft SUSY breaking terms in KKLT model are not phenomenological viable.…
It has been argued that supergravity models of inflation with vanishing sound speeds, $c_s$, lead to an unbounded growth in the production rate of gravitinos. We consider several models of inflation to delineate the conditions for which…
We study the back-reaction of moduli fields on the inflaton potential in generic models of F-term inflation. We derive the moduli corrections as a power series in the ratio of Hubble scale and modulus mass. The general result is illustrated…