Related papers: Overproduction of cosmic superstrings
Closed string tachyon condensation resolves the singularities of nonsupersymmetric orbifolds, however the resolved space typically has fewer D-brane charges than that of the orbifold. The description of the tachyon condensation process via…
I will briefly review the formation and evolution of cosmic superstrings, in the context of brane-world cosmological models within M-theory. These objects can play the role of cosmic strings, offering a variety of astrophysical…
We investigate the embedding of brane inflation into stable compactifications of string theory. At first sight a warped compactification geometry seems to produce a naturally flat inflaton potential, evading one well-known difficulty of…
In this short note we present a mathematical interpretation of tachyon condensation on (three dimensional) orbifolds within the framework of boundary string field theory (BSFT). We explicitly show that important parts of decay modes in…
Cosmological inflation and topological defects have been considered for a long time, either in disagreement or in competition. On the one hand an inflationary era is required to solve the shortcomings of the hot big bang model, while on the…
We point out some intriguing analogies between field theoretic solitons (topological defects) and D-branes. Annihilating soliton-antisoliton pairs can produce stable solitons of lower dimensionality. Solitons that localize massless gauge…
Scalar field theories with appropriate potentials in Minkowski space can have time-dependent classical solutions containing topological defects which correspond to S-branes - i.e. branes all of whose tangential dimensions are spacelike. It…
We present an improved effective action for the D-brane-anti-D-brane system obtained from boundary superstring field theory. Although the action looks highly non-trivial, it has simple explicit multi-vortex (i.e. codimension-2 multi-BPS…
In cosmological models where local cosmic strings are formed at the end of a period of inflation, the perturbations are seeded both by the defects and by the quantum fluctuations. In a subset of these models, for example those based on…
The influence of higher-order terms in the K\"{a}hler potential of the supergravity D-term inflation model on the density perturbation is studied. We show that these terms can make the inflaton potential flatter, which lowers the energy…
A model of tachyon inflation is proposed in the framework of holographic cosmology. The model is based on a holographic braneworld scenario with a D3-brane located at the holographic boundary of an asymptotic ADS$_5$ bulk. The tachyon field…
Dvali and Shifman have proposed a field-theoretic mechanism for localizing gauge fields to "branes" in higher dimensional spaces using confinement in a bulk gauge theory. The resulting objects have a number of qualitative features in common…
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…
It is shown that classical decay of unstable D-branes in bosonic and superstring theories produces pressureless gas with non-zero energy density. The energy density is stored in the open string fields, even though around the minimum of the…
We describe string production after angled brane inflation. First, we point out that there was a discrepancy in previous discussions. The expected tension of the cosmic string calculated from the four-dimensional effective Lagrangian did…
We consider hybrid inflation in the braneworld scenario. In particular, we consider inflation in global supersymmetry with the D-terms in the scalar potential for the inflaton field to be the dominant ones (D-term inflation). We find that…
"Brane Supersymmetry Breaking" is a peculiar string-scale mechanism that can unpair Bose and Fermi excitations in orientifold models. It results from the simultaneous presence, in the vacuum, of collections of D-branes and orientifolds that…
We study cosmological defect formation after brane inflation. The cosmological defects are corresponding to the branes that have less than three spacial dimensions in the uncompactified spacetime. Contrary to the previous arguments,…
We consider a D-brane probe in unstable string background associated with flux branes. The twist in spacetime metric reponsible for the supersymmetry breaking is shown to manifest itself in mixing of open Wilson lines with the phases of…
Using S(pacelike)-branes defined through rolling tachyon solutions, we show how the dynamical formation of D(irichlet)-branes and strings in tachyon condensation can be understood. Specifically we present solutions of S-brane actions…