Related papers: Type II Small Stringy Black Holes, Probe Branes an…
Integrability occupies an increasingly important role in direct tests of the AdS/CFT correspondence. Integrable structures have appeared in both planar N=4 super Yang-Mills theory and type IIB superstring theory on AdS_5 x S^5. A…
We consider pure D3-brane configurations of IIB string theory which lead to supersymmetric solutions containing an AdS$_3$ factor. They can provide new examples of AdS$_3$/CFT$_2$ examples on D3-branes whose worldvolume is partially…
The adS_{p+2} x S^{d-p-2} geometry of the near horizon branes is promoted to a supergeometry: the solution of the supergravity constraints for the vielbein, connection and form superfields are found. This supergeometry can be used for the…
We construct a family of supersymmetric solutions to AdS supergravity in three dimensions, that correspond to type IIB seven branes wrapped on an internal S3xT4. These solutions are generalizations of the three dimensional Goedel universe…
Supersymmetry of five dimensional string solutions is examined in the context of gauged D=5, N=2 supergravity coupled to abelian vector multiplets. We find magnetic black strings preserving one quarter of supersymmetry and approaching the…
The type IIA superstring partition function Z_IIA on the euclidean attractor geometry AdS_2 x S^2 x CY_3, computes the modified elliptic genus Z_BH of the associated black hole. The hybrid formalism of superstrings defined as a conformally…
We find examples of non-supersymmetric attractors in Type II string theory compactified on a Calabi Yau three-fold. For a non-supersymmetric attractor the fixed values to which the moduli are drawn at the horizon must minimise an effective…
We use recently established AdS$_6$/CFT$_5$ dualities to count the microstates of magnetically charged AdS$_6 \times S^2 \times \Sigma$ black holes in Type IIB. The near-horizon limit is described by solutions with AdS$_2 \times…
The quantum corrections to the counting of statistical entropy for the 5+1-dimensional extremal black string in type-IIB supergravity with two observers are studied using anomalous Wess-Zumino actions for the corresponding intersecting…
A simple relationship of the form Z_BH = |Z_top|^2 is conjectured, where Z_BH is a supersymmetric partition function for a four-dimensional BPS black hole in a Calabi-Yau compactification of Type II superstring theory and Z_top is a…
In [1] the horizon fluffs proposal is put forward to identify microstates of generic non-extremal three-dimensional Banados-Teitelboim-Zanelli (BTZ) black holes. The proposal is that black hole microstates, which were dubbed as horizon…
We study $\textrm{AdS}_2\times S^4 \times S^2 \times \Sigma_2$ solutions in type IIB string theory arising from D1 -- D3 -- NS5 brane intersections. These backgrounds enjoy sixteen supercharges and the corresponding internal geometry is…
At low energies, interactions of massless particles in type II strings compactified on a torus $T^d$ are described by an effective Wilsonian action $\mathcal{S}(\Lambda)$, consisting of the usual supergravity Lagrangian supplemented by an…
The AdS/CFT correspondence of elementary string theory has been recently suggested as a ``microscopic'' approach to QCD string theory in various dimensions. We use the microscopic theory to show that the ultraviolet regime on the string…
We investigate the conformal string $\sigma $-model corresponding to a general five-dimensional non-extremal black hole solution. In the horizon region the theory reduces to an exactly solvable conformal field theory. We determine the…
By assuming the existence of a novel multipronged string state for D-particles interacting with D-brane intersections in type IIA string theory, we are able to derive a quantum mechanical description of supersymmetric Reissner-Nordstrom…
String theory on AdS3 space-times with boundary conditions that allow for black hole states has global asymptotic symmetries which include an infinite dimensional conformal algebra. Using the conformal current algebra for sigma-models on…
We search for a possible bosonic (i.e. non-supersymmetric) string/gauge theory correspondence by using IIB and 0B strings as a guide. Our construction is based on the low-energy bosonic string effective action modified by an extra form…
Many three-dimensional $\mathcal{N}=2$ SCFTs admit a universal partial topological twist when placed on hyperbolic Riemann surfaces. We exploit this fact to derive a universal formula which relates the planar limit of the topologically…
This Ph.D. thesis investigates effective field and string theories in which supersymmetry is realized and broken in various ways. Chapter 1 addresses effective theories with nonlinearly realized supersymmetry, constructed using the…