Related papers: Modular symmetry in magnetized/intersecting D-bran…
We present the explicit form of the four-dimensional effective supergravity action which describes low-energy physics of the Randall--Sundrum model with moduli fields in the bulk and charged chiral matter living on the branes. The…
We examine the defect gauge theory on two perpendicular D3-branes with a 1+1 dimensional intersection, consisting of $U(1)$ fields on the D3-branes and charged hypermultiplets on the intersection. We argue that this gauge theory must have a…
We review some aspects of D-instantons in intersecting D-brane models. In particular, we present applications of the recently proposed instanton calculus to computations of charged matter superpotential couplings and corrections to the…
In this set of lectures various properties of D-branes are discussed. After reviewing the basics, we discuss unstable D-brane/anti-D-brane systems, a subject pioneered by Sen. Following him, we discuss the construction of the non-BPS…
A large class of equivalence relations between the moduli spaces of instantons on ALE spaces and the Higgs branches of supersymmetric Yang-Mills theories, are found by means of a certain kind of duality transformation between brane…
We show that all supersymmetric Type IIA D-branes can be constructed as bound states of a certain number of unstable non-supersymmetric Type IIA D9-branes. This string-theoretical construction demonstrates that D-brane charges in Type IIA…
We study N=1 four dimensional gauge theories as the world volume theory of D4-branes between NS 5-branes. We find constructions for a number of known field theory dualities involving $SU(N_c)\times SU(N_c')$ groups, coupled by matter fields…
A flat 3-brane probing a five dimensional anti-de Sitter space has the same symmetries and symmetry breaking pattern as one probing a five dimensional de Sitter space with two time directions. Despite the seemingly different physical set…
Distributional sources of matter on codimension-two and higher branes are only well-defined as regularized objects. Nevertheless, intuition from effective field theory suggests that the low-energy physics on such branes should be…
An approach towards a statistical survey of four dimensional supersymmetric vacua in the string theory landscape is described and illustrated with three examples of ensembles of intersecting D-brane models. The question whether it is…
Recently, an exact description of instanton corrections to the moduli spaces of 4d N=2 supersymmetric gauge theories compactified on a circle and Calabi-Yau compactifications of Type II superstring theories was found. The equations…
The low energy effective field theory of type II D4-branes coupled to bulk supergravity fields is used to investigate {\it quantum} effects for D4-branes in the D0 supergravity background. Classically, the D4-branes are unaffected by this…
Metastable supersymmetry breaking configurations of D-branes and NS5-branes in string theory often owe their existence to classical gravitational interactions between the branes. We show that in the effective theory of the light fields,…
We discuss various D-brane configurations in 4-dimensional orbifold compactifications of type II superstring theory which are point-like 0-branes from the 4-dimensional space-time point of view. We analyze their interactions and compute the…
This introductory part of the author's PhD compilation thesis discusses non-perturbative aspects of string theory, with focus on D-instantons which play key roles in the context of string phenomenology and dualities. By translating ideas…
The effective approach is applied to the analysis of inflationary magnetogenesis. Rather than assuming a particular underlying description, all the generally covariant terms potentially appearing with four space-time derivatives in the…
We show that twisted reduced models can be interpreted as noncommutative Yang-Mills theory. Based upon this correspondence, we obtain noncommutative Yang-Mills theory with D-brane backgrounds in IIB matrix model. We propose that IIB matrix…
We analyze the modular properties of D3-brane instanton corrections to the hypermultiplet moduli space in type IIB string theory compactified on a Calabi-Yau threefold. In Part I, we found a necessary condition for the existence of an…
We investigate cosmological constraints on phenomenological models with discrete gauge symmetries by discussing the radiation of standard model particles from Aharonov-Bohm strings. Using intersecting D-brane models in Type IIA string…
We study recombinations of D-brane systems intersecting at more than one angle using super Yang-Mills theory. We find the condensation of an off-diagonal tachyon mode relates to the recombination, as was clarified for branes at one angle in…