Related papers: p-adic Strings and their Applications
We compute the one-loop partition function for quadratic tachyon background in open string theory. Both closed and open string representations are developed. Using these representations we study the one-loop divergences in the partition…
We investigate the cosmological solutions in closed bosonic string theory in the presence of non zero tachyon condensate. We specifically obtain time dependent solutions which describe an anisotropic universe. We also discuss the nature of…
This talk begins with some history and basic facts about string theory and its connections with strong interactions. Comparisons of stacks of Dirichlet branes with curved backgrounds produced by them are used to motivate the AdS/CFT…
Alternative gauge choices for worldsheet supersymmetry can elucidate dynamical phenomena obscured in the usual superconformal gauge. In the particular example of the tachyonic $E_8$ heterotic string, we use a judicious gauge choice to show…
The potential of the closed bosonic bulk tachyon is investigated using $\mathcal{N}~=~1$ closed superstring field theory formulated around Berkovits' and Vafas embedding of the bosonic string into the superstring. From this point of view…
Assuming that around the tachyon vacuum the kinetic term of cubic open string field theory is made purely of ghost operators we are led to gauge invariant actions which manifestly implement the absence of open string dynamics around this…
We study the condensation of closed string tachyons as a time-dependent process. In particular, we study tachyons whose wave functions are either space-filling or localized in a compact space, and whose masses are small in string units; our…
In four decades of string theory research, only a handful of non-supersymmetric tachyon-free strings with only one neutral scalar at tree level were found. We construct new such non-supersymmetric tachyon-free string theories using…
This dissertation consists of a comprehensive and pedagogical review of Maldacena's original derivation of the AdS/CFT correspondence and the main topics of string theory necessary to understand it. The large $N$ expansion of Yang-Mills…
A non-supersymmetric ten-dimensional open string theory is constructed as an orbifold of type I string theory, and as an orientifold of the bosonic type B theory. It is purely bosonic, and cancellation of massless tadpoles requires the…
Axionic cosmic string solutions are investigated in a superstring motivated model with a pseudo-anomalous U(1) gauge symmetry. The inclusion of a gauge field and spatially varying dilaton allow local defect solutions with finite energy per…
Unstable, non-BPS D-branes in weakly coupled ten dimensional string theory have many mysterious properties. Among other things, it is not clear what sets their tension, what is their relation to the better understood BPS D-branes, and why…
We discuss the fate of certain tachyonic closed string theories from two perspectives. In both cases our approach involves studying directly configurations with finite negative tree-level cosmological constant. Closed string analogues of…
The tachyon effective field theory describing the dynamics of a non-BPS D-$p$-brane has electric flux tube solutions where the electric field is at its critical value and the tachyon is at its vacuum. It has been suggested that these…
These notes are an expanded version of a review lecture on closed string tachyon condensation at the RTN workshop in Copenhagen in September 2003. We begin with a lightning review of open string tachyon condensation, and then proceed to…
We present an exact solution of superstring theory that interpolates in time between an initial type 0 phase and a final phase whose physics is exactly that of the bosonic string. The initial theory is deformed by closed-string tachyon…
We propose a refinement of the physical picture describing different vacua in bosonic string theory. The vacua with closed strings and open strings are connected by the string field theory version of the Higgs mechanism, generalizing the…
The boundary string field theory approach is used to evaluate the one-loop tachyon potential. We first discuss the boundary condition at the two boundaries on annulus diagram and then the exact form of corrected potentials at zero and high…
Closed string tachyons have long been somewhat mysterious. We note that there is often a regime in the classical moduli space in which one can systematically compute the effective action for such fields. In this regime, the tachyon is…
We consider non-supersymmetric four-dimensional closed string theories constructed out of tensor products of N=2 minimal models. Generically such theories have closed string tachyons, but these may be removed either by choosing a…