Related papers: Comparing Infrared Dirac-Born-Infeld Brane Inflati…
The dominant method of energy loss by a loop of cosmic D-strings in models of warped brane inflation is studied. It is shown that the energy loss via Ramond-Ramond field radiation can dominate by many orders of magnitude over the energy…
We develop a formalism to study non-local higher-dimensional effects in braneworld scenarios from a four-dimensional effective theory point of view and check it against the well-known Garriga-Tanaka result in the appropriate limit. We then…
In this paper we show how the string landscape can be constrained using observational data. We illustrate this idea by focusing on Fibre Inflation which is a promising class of string inflationary models in type IIB flux compactifications.…
We analyze a class of generalized inflationary models proposed in Ref. [1], known as $\beta$-exponential inflation. We show that this kind of potential can arise in the context of brane cosmology, where the field describing the size of the…
A long period of inflation can be triggered when the inflaton is held up on the top of a steep potential by the infrared end of a warped space. We first study the field theory description of such a model. We then embed it in the flux…
The Dirac-Born-Infeld (DBI) action has been widely studied as an interesting example of a model of k-inflation in which the sound speed of the cosmological perturbations differs from unity. In this article we consider a scalar-tensor theory…
We discuss a new mechanism of obtaining a period of cosmological inflation in the context of string theory. This mechanism is based on embedded defects which form dynamically on higher dimensional D-branes. Such defects generate topological…
We reanalyze brane inflation with brane-brane interactions at an angle, which include the special case of brane-anti-brane interaction. If nature is described by a stringy realization of the brane world scenario today (with arbitrary…
Some classes of inflationary models naturally introduce two distinct metrics/frames, and their equivalence in terms of observables has often been put in question. D-brane inflation proposes candidates for an inflaton embedded in the string…
We study cosmological inflation on a warped DGP braneworld where inflaton field is non-minimally coupled to induced gravity on the brane. We present a detailed calculation of the perturbations and inflation parameters both in Jordan and…
In recent years, inflationary models have been studied from different perspectives using different conditions. Now, in this paper, we want to investigate the inverse monomial Inflation $(IMI)$ on the brane. We limit our results to the…
This thesis is dedicated to the study of inflationary scenarios based on string theory. Inflation is a brief period of accelerated expansion in the very early Universe which gives natural explanations for problems of the Standard Big Bang…
We calculate the amplitude of gravitational waves produced by inflation on a de Sitter brane embedded in five-dimensional anti-de Sitter bulk spacetime, extending previous calculations in Randall-Sundrum type cosmology to include the effect…
We construct an inflation model on the Randall-Sundrum I (RSI) brane where a bulk scalar field stabilizes the inter-brane separation. We study impact of the bulk scalar field on the inflationary dynamics on the brane. We proceed in two…
We examine observational constraints on chaotic inflation models in the Randall-Sundrum Type II braneworld. If inflation takes place in the high-energy regime, the perturbations produced by the quadratic potential are further from…
Inflation in a five-dimensional brane world model with two boundary branes is studied. We make use of the moduli space approximation whereby the low energy theory reduces to a four-dimensional biscalar-tensor gravity plus a minimally…
We investigate the early universe evolution in the context of brane inflation driven by a supergravity-inspired $\arctan$ potential. We performed a slow-roll and a semi-analytical reheating analyses and obtained constraints on the…
We investigate in the context of brane inflation the possibility of additional light scalar fields generating significant power spectrum and non-Gaussianities at the end of inflation affecting the CMB scale observations. We consider the…
We derive the noncommutative Dirac-Born-Infeld action for the $D$-brane, which governs dynamics of $D$-brane with a NS-NS $B$-field in the low energy regime. Depending on some details of the path integral prescriptions, both ordinary…
In this paper we consider a class of inflation models on the brane where the dominant part of the inflaton scalar potential does not depend on the inflaton field value during inflation. In particular, we consider supernatural inflation, its…