Related papers: Defect Formation with Bulk Fields
We study the effect of tachyon condensation on a brane antibrane pair in superstring theory separated in the transverse direction. The static properties of the tachyon potential analyzed using level truncated string field theory reproduces…
We consider cosmological consequences of string theory tachyon condensation. We show that it is very difficult to obtain inflation in the simplest versions of this theory. Typically, inflation in these theories could occur only at…
We show how the motion through the extra dimensions of a gas of branes and antibranes can, under certain circumstances, produce an era of inflation as seen by observers trapped on a 3-brane, with the inflaton being the inter-brane…
Hybrid inflation within supersymmetric grand unified theories, as well as inflation through brane collisions within braneworld cosmological models, lead to the formation of one-dimensional defects. Observational data, mainly from the cosmic…
We propose a new model of inflation in the framework of brane cosmology in the presence of tachyonic field. we derive the expressions for the model parameters in brane inflation, and estimate the observable parameters numerically and find…
In this paper we point out the inevitability of an explosive production of gauge field and gravity wave during an open string tachyon condensation in a cosmological setting. We will be particularly studying an example of brane-anti-brane…
In this lecture I will review the present status of 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…
We analyse the cosmological implications of brane-antibrane systems in string-theoretic orbifold and orientifold models. In a class of realistic models, consistency conditions require branes and antibranes to be stuck at different fixed…
In brane inflationary scenarios, the cosmological perturbations are supposed to originate from the vacuum fluctuations of the inflaton field corresponding to the position of the brane. We show that a significant, and possibly dominant,…
We propose that under certain conditions the universal open string tachyon can drive topological inflation in moduli stabilised frameworks. Namely, the presence of electric field in the world volume of the D-brane can slow down its decay…
Among the multiple 5D thick braneworld models that have been proposed in the last years, in order to address several open problems in modern physics, there is a specific one involving a tachyonic bulk scalar field. Delving into this…
We study tachyon condensation on brane-antibrane systems in orbifold theories from the viewpoint of boundary string field theory. We show that the condensation of holomorphic tachyon fields generates various fractional D-branes. The…
We study the cosmological particle creation in the tachyon inflation based on the D-brane dynamics in the RSII model extended to include matter in the bulk. The presence of matter modifies the warp factor which results in two effects: a…
Modern cosmology provides a connection between the physics of particles and fields and observational cosmology. Making use of this link, a wealth of new observational data can be utilized to explore and constrain theories of fundamental…
We propose a new mechanism to generate density perturbations in inflationary models. Spatial fluctuations in the decay rate of the inflaton field to ordinary matter lead to fluctuations in the reheating temperature. We argue that in most…
Thermal inflation is an attractive idea to dilute cosmic density of unwanted particles such as moduli fields which cause cosmological difficulties. However, it also dilutes preexisting baryon asymmetry and some viable baryogenesis is…
In brane cosmology, the Big Bang is hypothesized to occur by the annihilation of the brane-anti-brane pair in a collision, where the branes are three-dimensional objects in a higher-dimensional Universe. Spontaneous symmetry breaking…
We compute the power spectrum of super-horizon curvature perturbations generated during a late period of thermal inflation, taking into account fluctuation-dissipation effects resulting from the scalar flaton field's interactions with 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…
We propose a mechanism by which the inflaton can generate baryogenesis, by taking the inflaton to be a complex scalar field with a weakly broken global symmetry and present a new version of the Affleck-Dine mechanism. The smallness of the…