Related papers: BPS branes in discrete torsion orbifolds
We present a formal supersymmetric solution of type IIB supergravity generalizing previously known solutions corresponding to D3 branes to geometries without an orthogonal split between parallel and transverse directions. The metric is…
Tensionless super-p-branes in a generalized superspace with additional tensorial central charge coordinates may provide an extended object model for BPS preons, i.e. for the hypothetical constituents of M-theory preserving 31 of 32…
We discuss D-brane dynamics in orbifold compactifications of type II superstring theory. We compute the interaction potential between two D-branes moving with constant velocities and give a field theory interpretation of it in the large…
We address the delocalization of low dimensional D-branes and NS-branes when they are a part of a higher dimensional BPS black brane, and the homogeneity of the resulting horizon. We show that the effective delocalization of such branes is…
In this paper we introduce the concept of Deligne cohomology of an orbifold. We prove that the third Deligne cohomology group of a smooth \'{e}tale groupoid classify gerbes with connection over the groupoid. We argue that the $B$-field and…
The non-commutative algebra which defines the theory of zero-branes on $T^4/Z_2$ allows a unified description of moduli spaces associated with zero-branes, two-branes and four-branes on the orbifold space. Bundles on a dual space $\hat…
We discuss deformations of orbifold singularities on tilted tori in the context of Type IIA orientifold model building with D6-branes on special Lagrangian cycles. Starting from $T^6/(\mathbb{Z}_2 \times \mathbb{Z}_2)$, we mod out an…
In the first lecture, we discuss basic aspects of worldsheet and penta-brane instantons as well as (unoriented) D-brane instantons, which is our main focus here, and threshold corrections to BPS-saturated couplings. The second lecture is…
We present a geometric approach to D-brane model building on the non-factorisable torus backgrounds of $T^6/\mathbb{Z}_4$, which are $A_3 \times A_3$ and $A_3 \times A_1 \times B_2$. Based on the counting of `short' supersymmetric…
We extend previous results on generalized calibrations to describe supersymmetric branes in supergravity backgrounds with diverse fields turned on, and provide several new classes of examples. As an important application, we show that…
We study a thick and Z_2 symmetric braneworld model with a non-minimally coupled bulk scalar. Several analytic solutions are found. There are two categories of the brane configuration: standard branes and deformed ones. The former is just…
In this short note we discuss discrete torsion in orientifolds. In particular, we apply the physical understanding of discrete torsion worked out several years ago, as group actions on B fields, to the case of orientifolds, and recover some…
As a step toward constructing realistic brane world models in string theory, we consider the interactions of a pair of non-BPS branes. We construct a dyonic generalization of the non-BPS branes first constructed by Bergman, Gaberdiel and…
In this work we propose new non-commutative gauge theories that describe the dynamics of branes localized along twisted conjugacy classes on group manifolds. Our proposal is based on a careful analysis of the exact microscopic solution and…
Nature harbors crystals of dimensionality ($d$) only up to three. Here we introduce the notion of \emph{projected topological branes} (PTBs): Lower-dimensional branes embedded in higher-dimensional parent topological crystals, constructed…
We propose a Chern-Simons term for N coinciding non-BPS D-branes. Demanding full U(N) invariance and compatibility with T-duality, it is shown that it is necessary to introduce new interaction terms, through which the non-BPS D-branes…
We give a pedagogical introduction to D-brane instanton effects in vacuum configurations with open and unoriented strings. We focus on quiver gauge theories for unoriented D-branes at orbifold singularities and describe in some detail the…
We study pairs of planar D-branes intersecting on null hypersurfaces, and other related configurations. These are supersymmetric and have finite energy density. They provide open-string analogues of the parabolic orbifold and null-fluxbrane…
We study the embedding of D(8-p)-branes in the background geometry of parallel Dp-branes for $p\le 6$. The D(8-p)-brane is extended along the directions orthogonal to the Dp-branes of the background. The D(8-p)-brane configuration is…
In this PhD thesis the low energy effective actions for D-branes and the M5-brane are used to analyze the dynamics of brane probes moving in the geometry created by diverse supergravity backgrounds. It begins with an introduction to string…