Related papers: U(1) mixing and D-brane linear equivalence
Embeddings of the standard model in type II string theory typically contain a variety of U(1) gauge factors arising from D-branes in the bulk. In general, there is no reason why only one of these - the one corresponding to weak hypercharge…
Type II string compactifications to 4d generically contain massless Ramond-Ramond U(1) gauge symmetries. However there is no massless matter charged under these U(1)'s, which makes a priori difficult to measure any physical consequences of…
We employ generalized complex geometry to investigate supersymmetric embeddings of D-brane probes in a large class of SU(2) structure manifolds. This class includes the gravity dual of mass deformation and marginal beta deformation of N=4…
For recently constructed classes of D6-brane models, yielding the Standard Model fermion spectrum and gauge symmetry, we compute lower bounds on the masses of new U(1) fields that such models predict in addition to the hypercharge $U(1)_Y$.…
It is known that hidden U(1) gauge factors can couple to visible U(1)'s through Kinetic Mixing. This phenomenon is shown generically to occur in nonsupersymmetric string set-ups, between branes and antibranes. Kinetic Mixing acts either to…
We consider a generic scenario of spontaneous breaking of supersymmetry in the hidden sector within N=1 supersymmetric orientifold compactifications of type II string theories with D-branes that support semi-realistic chiral gauge theories.…
We consider the D2-brane probe action in the gravity background dual to N coincident Dp-branes by treating the separation between the D2- and Dp-branes as a nondynamical parameter for $p=2,4,6$. The gauge coupling, the core size of 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 study D-brane inspired models with U(3) x U(2) x U(1)^N gauge symmetry in the context of split supersymmetry. We consider configurations with one, two and three (N=1,2,3) abelian branes and derive all hypercharge embeddings which imply a…
We reconsider the problem of U(1) flux and D0-charge for D-branes in the WZW model and investigate the relationship between the different definitions that have been proposed recently. We identify the D0-charge as a particular reduction of a…
We consider chains of generalized submanifolds, as defined by Gualtieri in the context of generalized complex geometry, and define a boundary operator that acts on them. This allows us to define generalized cycles and the corresponding…
We describe the basic features of model building in the context of intersecting D-branes. As an example, a D-brane inspired construction with U(3)_C X U(3)_L X U(3)_R gauge symmetry is proposed -which is the analogue of the Trinification…
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…
Several aspects concerning the physics of D-branes in Type II flux compactifications preserving minimal N=1 supersymmetry in four dimensions are considered. It is shown how these vacua are completely characterized in terms of properly…
We systematically search intersecting D-brane models, which just realize the Standard Model chiral matter contents and gauge symmetry. We construct new classes of non-supersymmetric Standard Model-like models. We also study gauge coupling…
The U(1) gauge theory on a D3-brane with non-commutative worldvolume is shown to admit BIon-like solutions which saturate a BPS bound on the energy. The mapping of these solutions to ordinary fields is found exactly, namely…
We investigate D-brane instanton contributions to R^4 couplings in any toroidal compactification of type II theories. Starting from the 11D supergravity one-loop four-graviton amplitude computed by Green, Gutperle and Vanhove, we derive the…
Kinetic mixing between gauge fields of different $U(1)$ factors is a well-studied phenomenon in 4d EFT. In string compactifications with $U(1)$s from sequestered D-brane sectors, kinetic mixing becomes a key target for the UV prediction of…
A method of determining the mass spectrum of BPS D-branes in any phase limit of a gauged linear sigma model is introduced. A ring associated to monodromy is defined and one considers K-theory to be a module over this ring. A simple but…
We elucidate the structure of D terms in N=1 orientifold compactifications with fluxes. As a case study, we consider a simple orbifold of the type-IIA theory with D6-branes at angles, O6-planes and general NSNS, RR and Scherk-Schwarz…