Related papers: Post Inflationary Behaviour of String Moduli
A survey of solutions to the cosmological moduli problem in string theory. The only extant proposal which may work is Intermediate Scale Inflation as proposed by Randall and Thomas. Supersymmetry preserving dynamics which could give large…
We propose a mechanism of reheating after inflation in multi-throat scenarios of warped extra dimensions. Validity of an effective field theory on the standard model (SM) brane requires that the position of the SM brane during inflation be…
We obtain the non-equilibrium effective action of an inflaton like scalar field --the system-- by tracing over sub Hubble degrees of freedom of "environmental" light scalar fields. The effective action is stochastic leading to effective…
We study string inspired two-field models of large-field inflation based on axion monodromy in the presence of an interacting heavier modulus. This class of models has enough structure to approximate at least part of the backreaction…
Heterotic orbifold compactifications yield a myriad of models that reproduce many properties of the supersymmetric extension of the standard model and provide potential solutions to persisting problems of high energy physics, such as the…
We show that a particular class of effective low energy supergravity theories motivated by string theory can provide a promising framework for models of hybrid inflation in which the potential energy which drives inflation originates from…
In this work, we investigate how a smooth transition from a constant-roll to a slow-roll inflationary era may be realized, in the context of a canonical scalar field theory. We study in some detail the dynamical evolution of the…
The topic of this talk is a new inflationary model in the context of Type IIB string compactifications called Loop Blow-Up Inflation, presented in arXiv:2403.04831. The original Blow-Up Inflation model, whose potential was purely…
A model is developed in which the inflaton potential experiences a sudden small change in its second derivative (the effective mass of the inflaton). An exact treatment demonstrates that the resulting density perturbation has a quasi-flat…
We give a generic argument that string theory provides a natural setting for warm inflationary cosmology. We then explore a specific model with an inflaton modulus field coupled to fields that provide the continuous dissipation needed for…
We provide an analytical study of the coupling of short and long wavelength fluctuation modes during the initial phase of reheating in two field models like hybrid inflation. In these models, there is - at linear order in perturbation…
We study a possible origin of the anomalous suppression of the power spectrum at large angular scales in the cosmic microwave background within the framework of explicit string inflationary models where inflation is driven by a closed…
String theory abounds with light scalar fields (the dilaton and various moduli) which create a host of observational problems, and notably some serious cosmological difficulties similar to the ones associated with the Polonyi field in the…
We investigate multi-field inflationary scenarios with fields that drop out of the model in a staggered fashion. This feature is natural in certain multi-field inflationary setups within string theory; for instance, it can manifest itself…
In this paper we discuss the issues of supersymmetry breaking and moduli stabilization within the context of E_8 x E_8 heterotic orbifold constructions and, in particular, we focus on the class of "mini-landscape" models. In the…
We consider supergravity compactifications on 6-dimensional twisted tori, which are 5-torus fibrations of the circle. The motion of branes on such manifolds can lead to power-law potentials at low energy, that may be useful for inflation.…
We consider different cosmological aspects of Heterotic M-theory. In particular we look at the dynamical behaviour of the two relevant moduli in the theory, namely the length of the eleventh segment (pi rho) and the volume of the internal…
We present a type IIB 4D string model with stabilised moduli which is able to describe the history of the universe from inflation to quintessence. The underlying Calabi-Yau volume is controlled by two moduli which are stabilised by…
We describe a simple and efficient mechanism by which very heavy particles are copiously created from a primordial inflationary epoch. It works for scalar fields which are massless or very light during inflation and acquire a large mass…
We show that the scale of the inflationary potential may be the electroweak scale or even lower, while still generating an acceptable spectrum of primordial density perturbations. Thermal effects readily lead to the initial conditions…