Related papers: Tachyonic Inflation in a Warped String Background
Attempts to connect string theory with astrophysical observation are hampered by a jargon barrier, where an intimidating profusion of orientifolds, Kahler potentials, etc. dissuades cosmologists from attempting to work out the astrophysical…
This paper represents an in-depth treatment of the chain inflation scenario. We fully determine the evolution of the universe in the model, the necessary conditions in order to have a successful inflationary period, and the matching with…
We present a simple mechanism for obtaining large-field inflation, and hence a gravitational wave signature, from string theory compactified on twisted tori. For Nil manifolds, we obtain a leading inflationary potential proportional to…
The inflationary paradigm provides a robust description of the peculiar initial conditions which are required for the success of the Hot Big Bang model of cosmology, as well as of the recent precision measurements of temperature…
"Brane supersymmetry breaking" occurs in String Theory when the only available combinations of D-branes and orientifolds are not mutually BPS and yet do not introduce tree-level tachyon instabilities. It is characterized by the emergence of…
It is shown that Starobinsky-like potentials can be realized in non-geometric flux compactifications of string theory, where the inflaton involves an axion whose shift symmetry can protect UV-corrections to the scalar potential. For that…
We investigate a new mechanism for realizing slow roll inflation in string theory, based on the dynamics of p anti-D3 branes in a class of mildly warped flux compactifications. Attracted to the bottom of a warped conifold throat, the…
We compare the Infrared Dirac-Born-Infeld (IR DBI) brane inflation model to observations using a Bayesian analysis. The current data cannot distinguish it from the \LambdaCDM model, but is able to give interesting constraints on various…
Using DBI inflation as an example, we demonstrate that the detailed geometry of warped compactification can leave an imprint on the cosmic microwave background (CMB). We compute CMB observables for DBI inflation in a generic class of warped…
We analyze a distinctive mechanism for inflation in which particle production slows down a scalar field on a steep potential, and show how it descends from angular moduli in string compactifications. The analysis of density perturbations --…
We investigate the embedding of brane anti-brane inflation into a concrete type IIB string theory compactification with all moduli fixed. Specifically, we are considering a D3-brane, whose position represents the inflaton $\phi$, in a…
The eta problem is one of the most significant obstacles to building a successful inflationary model in string theory. Planck mass suppressed corrections to the inflaton potential generally lead to inflaton masses of order the Hubble scale…
An upper bound on the amplitude of the primordial gravitational wave spectrum generated during ultra-violet DBI inflation is derived. The bound is insensitive to the form of the inflaton potential and the warp factor of the compactified…
We show that, in constructions with additional intersecting D-branes, brane-antibrane inflation may naturally occur in a warm regime, such that strong dissipative effects damp the inflaton's motion, greatly alleviating the associated…
We discuss how Starobinsky-like inflation may emerge from dilaton dynamics in brane cosmology scenarios based on string theory, in which our universe is represented as a three-brane. The effective potential may acquire a constant term from…
We discuss the problem of tachyon condensation in the framework of background independent open string field theory. We show, in particular, that the computation of the string field theory action simplifies considerably if one looks at…
Overall, brane inflation is compatible with the recent analysis of the WMAP data. Here we explore the constraints of WMAP and 2dFGRS data on the various brane inflationary scenarios. Brane inflation naturally ends with the production of…
We develop a string-motivated dynamical Gauss--Bonnet completion of Starobinsky inflation. Since a constant Gauss--Bonnet term is topological in four dimensions, observable effects must arise from a modulus, dilaton, or compactification…
Considerable and ongoing effort is made to identify promising scalar field candidates in string theory to drive a cosmological period of inflation. At stake is the possibility that fundamental string parameters could be encoded in…
We study the motion of a (space filling) D3-brane at the tip of a warped deformed conifold, looking for inflationary trajectories. In our setup no anti D3-brane is present and the inflaton potential is induced by threshold corrections to…