Related papers: Fuzzy Cosets and their Gravity Duals
We consider space and time dependent fuzzy spheres $S^{2p}$ arising in $D1-D(2p+1)$ intersections in IIB string theory and collapsing D(2p)-branes in IIA string theory. In the case of $S^2$, where the periodic space and time-dependent…
A global superalgebra with 32 supercharges and all possible central extensions is studied in order to extract some general properties of duality and hidden dimensions in a theory that treats $p$-branes democratically. The maximal number of…
In this note we discuss D-branes on T^4/Z_2 using the boundary states formalism. Explicit formulas for the untwisted boundary states inherited from the underlying T^4 and twisted states corresponding to branes wrapping collapsed 2-cycles at…
We study a general configuration of parallel branes having co-dimension >2 situated inside a compact d-dimensional bulk space within the framework of a scalar and flux field coupled to gravity in D dimensions, such as arises in the bosonic…
We present five dimensional gauged supergravity with universal hypermultiplet on M_4 \times S^1 / Z_2 coupled supersymmetrically to three-branes located at the fixed points. The construction is extended to the smooth picture with auxiliary…
We discuss gauge fields on tori in diverse dimensions, mainly in two and four dimensions. We construct various explicit gauge fields which have some topological charges and find the Dirac zero modes in the background of the gauge fields. By…
We investigate an effective torsion curvature in a second order formalism underlying a two form world-volume dynamics in a $D_5$-brane. In particular, we consider the two form in presence of a background (open string) metric in a $U(1)$…
We construct classical solutions in quiver gauge theories on D0-branes probing toric del Pezzo singularities in Calabi-Yau manifolds. Our solutions represent D4-branes wrapped around fuzzy del Pezzo surfaces. We study the fluctuation…
A recent result concerning interacting theories of self-dual tensor gauge fields in six dimensions is generalized to include coupling to gravity. The formalism makes five of the six general coordinate invariances manifest, whereas the sixth…
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 this paper we obtain supersymmetric brane-like configurations in the vacuum of N=4 gauged $SU(2)\times SU(2)$ supergravity theory in four spacetime dimensions. Almost all of these vacuum solutions preserve either half or one quarter of…
We construct a fuzzy $S^4$, utilizing the fact that ${\bf CP}^3$ is an $S^2$ bundle over $S^4$. We find that a fuzzy $S^4$ can be described by a block-diagonal form whose embedding square matrix represents a fuzzy ${\bf CP}^3$. We discuss…
Bloch branes were introduced previously and are constructed in a system described by two real scalar fields coupled with gravity in (4, 1) dimensions in warped spacetime involving one extra dimension. This work investigates gravity on such…
We find broad classes of solutions to the field equations for d-dimensional gravity coupled to an antisymmetric tensor of arbitrary rank and a scalar field with non-vanishing potential. Our construction generates these configurations from…
In this Ph. D. Thesis we concentrate on the study of the extension of the AdS/CFT correspondence to theories with less supersymmetry. In particular, we search for the possibility of adding supersymmetric D-branes in type IIB supergravity…
Gauge/gravity dualities are investigated from the worldsheet point of view. In [arXiv:0706.1163] and [arXiv:0708.2463], a duality between 4d SYM and supergravity on AdS_5xS^5 has been partly explained by using an anisotropic scale…
We show that, in the context of dilaton gravity, a recently proposed democratic principle for intersection possibilities of branes winding around extra dimensions yield stabilization, even with the inclusion of momentum modes of the wrapped…
In matrix models, higher dimensional D-branes are obtained by imposing a noncommutative relation to coordinates of lower dimensional D-branes. On the other hand, a dual description of this noncommutative space is provided by higher…
We discuss dual formulations of D-brane intersections. The duality is between world volume field theories of different dimensionalities which both describe the same D-brane configuration but are valid in complementary regions of parameter…
The near-horizon region of Neveu-Schwarz fivebranes provides interesting examples of gauge/gravity duality. We revisit the structure of wrapped and/or intersecting fivebranes using the tools of null-gauged WZW models in worldsheet string…