相关论文: Strings, Branes, Schwarzian Action and Maximal Cha…

We investigate both from a qualitative as well as quantitative perspective the emergence of chaos in the QCD confining string in a magnetic field from a holographic viewpoint. We use an earlier developed bottom-up solution of the…

In this paper we study the conjectured dual operators to a near maximal giant graviton and their open string fluctuations in the large $N$ limit. Using matrix model estimates we show that the spectrum of states near the D-brane operator is…

It has long been thought that a highly excited string can be regarded as a black hole: the correspondence principle between strings and a black hole, while recent studies found that black holes are characterized by chaos. This suggests that…

We show how to construct chiral tachyon-free perturbative orientifold models, where supersymmetry is broken at the string scale on a collection of branes while, to lowest order, the bulk and the other branes are supersymmetric. In higher…

There is great interest in the construction of brane worlds, where matter and gravity are forced to be effective only in a lower dimensional surface , the brane . How these could appear as a consequence of string theory is a crucial…

This paper addresses several unsettled issues associated with string creation in systems of orthogonal Dp-D(8-p) branes. The interaction between the branes can be understood either from the closed string or open string picture. In the…

Based on a generalization of the string theoretic concept of D-brane probe, we propose a new approach to large N gauge theories which makes the holographic properties manifest. For any gauge theory, we define from first principles an…

The application of D-brane methods to large black holes whose Schwarzschild radius is larger than the compactification scale is problematic. Callan and Maldacena have suggested that despite apparent problems of strong interactions when the…

We investigate mechanisms that can trigger supersymmetry breaking in open string vacua. The focus is on backgrounds with D-branes and orientifold planes that have an exact string description, and allow to study some of the quantum effects…

Recent work has shown that unstable D-branes in two dimensional string theory are represented by eigenvalues in a dual matrix model. We elaborate on this proposal by showing how to systematically include higher order effects in string…

A review of various aspects of superstrings in background electromagnetic fields is presented. Topics covered include the Born-Infeld action, spectrum of open strings in background gauge fields, the Schwinger mechanism, finite-temperature…

In the cubic string field theory, using the gauge invariant operators corresponding to the on-shell closed string vertex operators, we have explicitly evaluated the decay amplitudes of two open string tachyons or gauge fields to one closed…

We study a defect conformal field theory describing D3-branes intersecting over two space-time dimensions. This theory admits an exact Lagrangian description which includes both two- and four-dimensional degrees of freedom, has (4,4)…

In this thesis we investigate some aspects of the dramatic consequences of supersymmetry breaking on string vacua. In particular, we focus on the issue of vacuum stability in ten-dimensional string models with broken, or without,…

We investigate chaotic dynamics in tree-level S-matrices describing the scattering of tachyons, photons and gravitons on highly excited open and closed bosonic strings, motivated by the string/black hole complementarity. The eigenphase…

We construct a general class of chiral four-dimensional string models with Scherk--Schwarz supersymmetry breaking, involving freely acting orbifolds. The basic ingredient is to combine an ordinary supersymmetry-preserving Z_N projection…

We study the effects of quantum production of open strings on the relativistic scattering of D-branes. We find strong corrections to the brane trajectory from copious production of highly-excited open strings, whose typical oscillator level…

We study brane-world models with variable brane tension and compute corrections to the horizon of a black string along the extra dimension. The four-dimensional geometry of the black string on the brane is obtained by means of the minimal…

It is well-known that Scherk-Schwarz compactifications in string theory have a tachyon in the closed string spectrum appearing for a critical value of a compact radius. The tachyon can be removed by an appropriate orientifold projection in…

We give a basic account of supersymmetric open strings and D-branes using the Green-Schwarz formalism, obtaining a manifestly spacetime supersymmetric description of their spectrum. In addition we discuss a mechanism whereby some of the…