Related papers: About The Enhancon Mechanism
We study the enhancon mechanism for fractional D-branes in conifold and orbifold backgrounds and show how it can resolve the repulson singularity of these geometries. In particular we show that the consistency of the excision process…
The enhancon mechanism removes a family of time-like singularities from certain supergravity spacetimes by forming a shell of branes on which the exterior geometry terminates. The problematic interior geometry is replaced by a new…
We reconsider supersymmetric five dimensional rotating charged black holes, and their description in terms of D-branes. By wrapping some of the branes on K3, we are able to explore the role of the enhancon mechanism in this system. We…
The presentation at Strings 2000 was intended to be in two main parts, but there was only time for part one. However both parts appeared on the online proceedings, and are also included in this document. The first part concerns an…
We present some results of studying certain axially symmetric supergravity geometries corresponding to a distribution of BPS D6-branes wrapped on K3, obtained as extremal limits of a rotating solution. The geometry's unphysical regions…
We study unphysical features of the BMPV black hole and how each can be resolved using the enhancon mechanism. We begin by reviewing how the enhancon mechanism resolves a class of repulson singularities which arise in the BMPV geometry when…
In my talk I shall consider the mechanism of self-expansion of a system of N D0-branes into high-dimensional non-commutative world-volume investigated by Harmark and Savvidy. Here D2-brane is formed due to the internal angular momentum of…
We study the `enhancon', a spherical hypersurface apparently made of D-branes, which arises in string theory studies of large N SU(N) pure gauge theories with eight supercharges. When the gauge theory is 2+1 dimensional, the enhancon is an…
We consider the N=2 gauge theory on N D7-branes wrapping K3, with D3-brane probes. In the large N limit, the D7-branes blow up to form an enhancon shell. We probe the region inside and outside the enhancon shell using the D3-branes, and…
Common wisdom asserts that bound excitons cannot form in high-dimensional (d>1) metallic structures because of their overwhelming screening and unavoidable resonance with nearby continuous bands. Strikingly, here we illustrate that this…
Supergravity solutions related to large N SU(N) pure gauge theories with eight supercharges have recently been shown to give rise to an ``enhancon'', a new type of hypersurface made of D-branes. We show that enhancons also arise in similar…
We consider the asymmetric orbifold that is obtained by acting with T-duality on a 4-torus, together with a shift along an extra circle. The chiral algebra of the resulting theory has non-trivial outer automorphisms that act as permutations…
We review orientifold constructions in the presence of magnetic backgrounds both in the open and closed sectors. Generically, the resulting orientifold models have a nice geometric description in terms of rotated D-branes and/or O-planes.…
D-branes on orbifolds with and without discrete torsion are analysed in a unified way using the boundary state formalism. For the example of the Z2 x Z2 orbifold it is found that both the theory with and without discrete torsion possess…
We study complex structure deformations of special Lagrangian cycles associated to fractional D-branes at $\mathbb{Z}_2$ singularities in Type II/$\Omega \mathcal{R}$ orientifold models. By means of solving hypersurface constraints, we show…
We study D1-branes on the fourfold $\C^4/(\Z_2\times\Z_2\times\Z_2)$, in the presence of discrete torsion. Discrete torsion is incorporated in the gauge theory of the D1-branes by considering a projective representation of the finite group…
The mechanism of recombination of intersecting D-branes is investigated within the framework of effective tachyon field theory. We regard the branes as the kink-type tachyon condensed states and use the effective two-tachyon Lagrangian to…
We derive D-brane gauge theories for C^3/Z_n x Z_n orbifolds with discrete torsion and study the moduli space of a D-brane at a point. We show that, as suggested in previous work, closed string moduli do not fully resolve the singularity,…
The low-energy supersymmetric quantum mechanics describing D-particles in the background of D8-branes and orientifold planes is analyzed in detail, including a careful discussion of Gauss' law and normal ordering of operators. This…
This thesis is devoted to the construction and study of D-branes in some curved space-times in string theory. On the one hand, those D-branes are described geometrically as submanifolds subject to Born-Infeld effective dynamics. On the…