Related papers: Exciting gauge field and gravitons in a brane-anti…
We investigate the spacetime-dependent condensation of the tachyon in effective field theories. Previous work identified singularities in the field which appear in finite time: infinite gradients at the kinks, and (in the eikonal…
In a linear dilaton background, it has been argued that an unstable D-brane can decay to the tachyon vacuum without leaving behind a remnant of tachyon matter. Here we address the question of how the D-brane can decay to the tachyon vacuum…
We study classical dynamics of an open string tachyon $T$ of unstable D$p$-brane coupled to the gauge field $A_\mu$. In the vacuum with vanishing potential, V=0, two fluid-like degrees of freedom, string fluid and tachyon matter, survive…
We study the spacetime decay to nothing in string theory and M-theory. First we recall a nonsupersymmetric version of heterotic M-theory, in which bubbles of nothing -- connecting the two E_8 boundaries by a throat -- are expected to be…
We study quantum corrections at the one loop level in open superstring tachyon condensation using the boundary string field theory (BSFT) method. We find that the tachyon field action has the same form as at the disc level, but with a…
We discuss the proposal of Hata and Kawano for the tachyon fluctuation around a solution of vacuum string field theory representing a D25 brane. We give a conformal field theory construction of their state -- a local insertion of a tachyon…
We propose a model of inflation in the framework of brane cosmology driven by background supergravity. Starting from bulk supergravity we construct the inflaton potential on the brane and employ it to investigate for the consequences to…
We propose a novel gravitational mechanism for the non-thermal production of dark matter driven by curvature-induced tachyonic instabilities after inflation. Departing from the commonly studied non-minimal couplings to gravity, our…
We study possible string theory compactifications which, in the low-energy limit, describe chaotic inflation with a stabilizer field. We first analyze type IIA setups where the inflationary potential arises from a D6-brane wrapping an…
We investigate the leading contribution to open string production in the time dependent background of the Brane Anti-Brane. This is a 1-loop diagram and we use Boundary Conformal Field Theory (BCFT) techniques to study it. We show that the…
The boundary state corresponding to the D$p$-brane with a transverse rotation in the presence of the Kalb-Ramond and tachyon background fields and a $U(1)$ internal field will be constructed. We shall investigate effects of the open string…
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…
String theory gives rise to various mechanisms to generate primordial inflation, of which ``brane inflation'' is one of the most widely considered. In this scenario, inflation takes place while two branes are approaching each other, and the…
In this paper we study non-perturbative instabilities in Anti de-Sitter vacua arising from flux compactifications of string models with broken supersymmetry. In the semi-classical limit, these processes drive the vacua towards lower fluxes,…
An overview is presented of some cosmological aspects of string theory. Recent developments are emphasised, especially the attempts to derive inflation or alternatives to inflation from the dynamics of branes in string theory. Time…
We elaborate on the decay of branes inside throat geometries that are supported by flux carrying charges opposite to the brane. Our main point is that such backgrounds necessarily have a local, possibly diverging, pile up of brane-charges…
We construct the world-volume action for non-BPS D-branes in type II string theories. This action is invariant under all the unbroken supersymmetries in the bulk, but these symmetries are realised as spontaneously broken symmetries in the…
We construct a hybrid-inflation model where the inflaton potential is generated radiatively, as gauge symmetries guarantee it to be accidentally flat at tree level. The model can be regarded as a small-field version of Natural Inflation,…
We study dynamics of rolling tachyon and Abelian gauge field on unstable D-branes, of which effective action is given by Born-Infeld type nonlocal action. Possible cosmological evolutions are also discussed. In the Einstein frame of string…
Within the framework of braneworlds, several interesting physical effects can be described in a wide range of energy scales, starting from high-energy physics to cosmology and low-energy physics. An usual way to generate a thick braneworld…