Related papers: Exciting gauge field and gravitons in a brane-anti…
We investigate brane inflation driven by two stacks of mobile branes in a throat. The stack closest to the bottom of the throat annihilates first with antibranes, resulting in particle production and a change of the equation of state…
We describe a simple mechanism that can lead to inflation within string-based brane-world scenarios. The idea is to start from a supersymmetric configuration with two parallel static Dp-branes, and slightly break the supersymmetry…
The naive low energy effective action of the tachyon and the U(1) gauge field obtained from string field theory does not correspond to the world volume action of unstable branes in bosonic string theory. We show that there exists a field…
In these notes we provide a pedagogical introduction to the subject of tachyon condensation in Witten's cubic bosonic open string field theory. We use both the low-energy Yang-Mills description and the language of string field theory to…
A coincident D-brane - anti-D-brane pair has a tachyonic mode. We present an argument showing that at the classical minimum of the tachyonic potential the negative energy density associated with the potential exactly cancels the sum of the…
We present a general set-up for inflation in string theory where the inflaton field corresponds to Wilson lines in compact space in the presence of magnetic fluxes. T-dualities and limits on the value of the magnetic fluxes relate this…
We propose a form of the effective action of the tachyon and gauge fields for brane-antibrane systems and non-BPS Dp-branes, written in terms of the supercurvature. Kink and vortex solutions with constant infinite gauge field strength…
We analyze observational constraints on the parameter space of tachyonic inflation with a Gaussian potential and discuss some predictions of this scenario. As was shown by Kofman and Linde, it is extremely problematic to achieve the…
We propose gauge theories in which the unstable branes and the fundamental string are realized as classical solutions. While the former are represented by domain wall like configurations of a scalar field coupled to the gauge field, the…
We propose a new scenario for D-term inflation which appears quite straightforwardly in the open string sector of intersecting brane models. We take the inflaton to be a chiral field in a bifundamental representation of the hidden sector…
It has been conjectured that at the stationary point of the tachyon potential for the non-BPS D-brane or brane-anti-D-brane pair, the negative energy density cancels the brane tension. We study this conjecture using a cubic superstring…
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…
Tachyon-Brane inflationary universe model in the context of a Chaplygin gas equation of state is studied. General conditions for this model to be realizable are discussed. In the high-energy limit and by using an exponential potential we…
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…
In this note we propose the use of an alternate action for the open string tachyon on a non-BPS $D3$-brane. At the classical level this action is precisely equivalent to the more commonly used DBI action, but involves an additional coupling…
Using the boundary state formalism and thermo field dynamics approach, we study a D$p$-brane at finite temperature in which the background Kalb-Ramond field, a $U(1)$ gauge potential, and tachyon field are turned on together with a general…
The axionic inflaton with the Chern-Simons coupling may generate U(1) gauge fields and charged particles simultaneously. In order to incorporate the backreaction from the charged particles on the gauge fields, we develop a procedure to…
Axions play a central role in many realizations of large field models of inflation and in recent alternative mechanisms for generating primordial tensor modes in small field models. If these axions couple to gauge fields, the coupling…
Models of inflation based on axions, which owe their popularity to the robustness against UV corrections, have also a very distinct class of signatures. The relevant interactions of the axion are a non-perturbative oscillating contribution…
We use open string field theory to study the dynamics of unstable branes in the bosonic string theory, in the background of a generic linear dilaton. We find a simple exact solution describing a dynamical interpolation between the…