Related papers: Electrified branes
We point out that models where gauge and charged matter fields live on the world volume of D3 branes can provide a weak string coupling description of the gauge coupling unification in the supersymmetric standard model at a scale of order…
We study the boundary states of D-branes wrapped around supersymmetric cycles in a general Calabi-Yau manifold. In particular, we show how the geometric data on the cycles are encoded in the boundary states. As an application, we analyze…
We explored a variety of brane configurations in our previous paper within the two derivative truncation of the unstable D9-brane effective theory. In this paper we extend our previous results with emphasis on the inclusion of the higher…
A zero-brane is used to probe non-threshold BPS bound states of (p, p+2,p+4)-branes. At long distances the stringy calculation agrees with the supergravity calculations. The supergravity description is given, using the interpretation of the…
In these notes we give an introduction to the concept of spaces with GxG-structure and their structured submanifolds. These objects generalise the classical notion of a calibrated submanifold. Therefore, they are interesting from a string…
In this paper we thermalize the type II superstrings in the GS formulation by applying the TFD formalism. The thermal boundary conditions on the thermal Hilbert space are obtained from the BPS $D$-brane boundary conditions at zero…
In this Ph.D. thesis, we study some aspects of strings and branes. We mainly focus on anomalous D-brane couplings and on non-supersymmetric branes. In Chapter 2, we illustrate three key concepts in a field theory context: duality,…
We consider type IIB superstring theory with embedded $D5$-brane and choose boundary conditions which preserve half of the initial supersymmetry. In the canonical approach that we use, boundary conditions are treated as canonical…
In this note, we apply a special metric ansatz to simplify the equations of motion for gravitational systems. Then we construct charged brane solutions in $D=n+p+2$ dimensions which have spherical symmetry of $S^n$ and translational…
We present special classes of orientifold models involving supersymmetry breaking via branes at angles. Type II superstring theories are compactified on a two torus times a four-dimensional orbifold. Combining worldsheet parity with a…
We consider freely acting orbifold compactifications, which interpolate in two possible decompactification limits between the supersymmetric type II string and the non-supersymmetric type 0 string. In particular we discuss how D-branes are…
We consider bound states of D-branes wrapped around cycles with non-trivial fundamental groups of finite order. We find a new mechanism for binding D-branes by turning on flat discrete abelian and non-abelian gauge fields on their…
Following our previous paper (hep-th/9909027), we generalize a supersymmetric boundary state so that arbitrary configuration of the gauge field coupled to the boundary of the worldsheet is incorpolated. This generalized boundary state is…
We propose a new analytical method for determining whether nonsupersymmetric probe branes embedded in nontrivial backgrounds are perturbatively stable or not. The method is based on a relationship between zero mass solutions of the relevant…
Warped supergravities with lower-dimensional branes provide consistent field-theoretic framework for discussion of important aspects of modern string theory physics. In particular, it is possible to study reliably supersymmetry breakdown…
Boundary states corresponding to wrapped D-branes in Calabi-Yau compactifications of type II strings are discussed using Gepner models. In particular boundary conditions corresponding to D-0 branes and D-instantons in four dimensions are…
We consider a model for tensionless (null) super p-branes with N chiral supersymmetries in ten dimensional flat space-time. After establishing the symmetries of the action, we give the general solution of the classical equations of motion…
We develop the concept of supersymmetry in singular spaces, apply it in an example for 3-branes in D=5 and comment on 8-branes in D=10. The new construction has an interpretation that the brane is a sink for the flux and requires adding to…
We perform a generalization of the geometrical approach to describing extended objects for studying the doubly supersymmetric twistor--like formulation of super--p--branes. Some basic features of embedding world supersurface into target…
Classical configurations of a M2-brane, a D2-brane and D0-branes are investigated in the background of an infinite array of M5-branes or NS5-branes. On the M2-brane, we discuss three kinds of configurations, such as a sphere, a cylinder and…