Related papers: Cosmological moduli problem in large volume scenar…
We study closed string axions in type IIB orientifold compactifications. We show that for natural values of the background fluxes the moduli stabilisation mechanism of the LARGE Volume Scenario (LVS) gives rise to an axiverse characterised…
Recently, few cosmological models with additional non-Riemannian volume form(s) have been proposed. In this article we use Supernovae type Ia experimental data to test one of these models which provides a unified description of both dark…
If inflation occurs after the breaking of Peccei-Quinn symmetry then large values of the breaking scale $F$, which are forbidden in conventional axion cosmology, are permitted, provided that we inhabit a region of the Multiverse where the…
Cosmological scaling solutions, which give rise to a scalar-field density proportional to a background fluid density during radiation and matter eras, are attractive to alleviate the energy scale problem of dark energy. In the presence of…
In this talk I discuss recent developments in moduli stabilisation, SUSY breaking and chiral D-brane models together with several interesting features of cosmological models built in the framework of type IIB string compactifications. I…
We investigate the Affleck-Dine baryogenesis after D-term inflation with a positive Hubble-induced mass term for a B-L flat direction. It stays at a large field value during D-term inflation, and just after inflation ends it starts to…
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…
The brane cosmology has invoked new challenges to the usual Big Bang cosmology. In this paper we present a brief account on thermal history of the post-inflationary brane cosmology. We have realized that it is not obvious that the…
The main aim of this paper is to provide a qualitative introduction to the cosmic inflation and its relationship with current cosmological observations. The inflationary model solves many of the fundamental problems that challenge the…
Recent anomalies in cosmic rays could be due to dark matter annihilation in our galaxy. In order to get the required large cross-section to explain the data while still obtaining the right relic density, we rely on a non standard thermal…
We study moduli stabilization by thermal effects in the cosmological context. The implementation of finite temperature, which spontaneously breaks supersymmetry, induces an effective potential at one loop level. At the points where extra…
In the framework of polynomial Palatini cosmology, we investigate a simple cosmological homogeneous and isotropic model with matter in the Einstein frame. We show that in this model during cosmic evolution, it appears the early inflation…
Problem of cosmological singularity of general relativity theory is discussed. The possible resolution of this problem in the framework of inflationary cosmology is proposed. Physical conditions leading to bouncing inflationary solutions in…
We consider moduli fields interacting with thermalized relativistic matter. We determine the temperature dependence of their damping rate and find it is dominated by thermal effects in the high temperature regime, i.e. for temperatures…
A radiative seesaw model with an inert doublet dark matter is a promising candidate which could explain the existence of neutrino masses, dark matter and baryon number asymmetry of the Universe, simultaneously. In addition to these issues,…
A brief account is given of large-scale structure modelling based on the assumption that the initial perturbations arise from inflation. A recap is made of the implications of inflation for large-scale structure; under the widely applicable…
We propose a new realization of axion monodromy inflation in which axion monodromy arises from torsional cycles in a type IIB compactification. A class of monomial potentials is obtained with specific values for the power index. Moreover,…
Multibubble solutions for a cosmological model which lead to thermal inflationary states due to a semi-classical tunneling of gravity are calculated.
If inflation scale is high, light scalars acquire large quantum fluctuations during inflation.If sufficiently long-lived, they will give rise to CDM isocurvature perturbations, which are highly constrained by the Planck data. Focusing on…
Moduli fields with Planck-suppressed couplings to light species are common in string compactifications. Decays of these moduli can reheat the universe at a late time and produce dark matter non-thermally. For generic moduli fields motivated…