Related papers: Orbits of Exceptional Groups, Duality and BPS Stat…

We review recent results in the study of regular four dimensional BPS black holes in toroidally compactified type II (or M) theory. We discuss the generating solution for this kind of black holes, its microscopic description(s), and compute…

One would often like to know when two a priori distinct extremal black p-brane solutions are in fact U-duality related. In the classical supergravity limit the answer for a large class of theories has been known for some time. However, in…

This thesis is focused on supersymmetric objects in gauged supergravities and their interpretation in string theory. Three particular theories are considered and analyzed: matter-coupled $d=4, 5$ abelian gauged supergravities with 8…

It has recently been proposed that a class of supersymmetric higher-derivative interactions in N=2 supergravity may encapsulate an infinite number of finite size corrections to the microscopic entropy of certain supersymmetric black holes.…

N=8 supergravity has a rich spectrum of black holes charged under the 56 U(1) gauge fields of the theory. Duality predicts that the entropy of these black holes is related to the quartic invariant of the E(7,7) group. We verify this…

We find solutions of the bosonic sector of gauged N=4, D=4 SU(2) $\times$ SU(2) supergravity, which represent dilaton black holes with toroidal or spherical event horizons. The axion is consistently truncated, and the gauge group is broken…

We review recent results in the study of attractor horizon geometries (with non-vanishing Bekenstein-Hawking entropy) of dyonic extremal d=4 black holes in supergravity. We focus on N=2, d=4 ungauged supergravity coupled to a number n_{V}…

We study extremal black holes, their ADM mass and area of the horizon in N = 8 supergravity. Contrary to intuition gained from N = 2, 4 theories, in N = 8 supergravity BPS states may become massless only at the boundary of moduli space. We…

The entropy of a half-BPS black hole in N=4 supersymmetric heterotic string compactification is independent of the details of the charge vector and is a function only of the norm of the charge vector calculated using the appropriate…

We find the topological entropy formula for all $N>2$ extended supergravities in five dimensions and the fixed scalar condition for the black-hole ``potential energy'' which extremizes the BPS mass. We comment upon the interpretation of…

We identify the states in string theory which are responsible for the entropy of near-extremal rotating four-dimensional black holes in $N=8$ supergravity. For black holes far from extremality (with no rotation), the Bekenstein-Hawking…

We determine and classify the electric-magnetic duality orbits of fluxes supporting asymptotically flat, extremal black branes in $D=4,5,6$ space-time dimensions in the so-called non-supersymmetric magic Maxwell-Einstein theories, which are…

We present duality invariant structure of the thermodynamic quantities of non-extreme black hole solutions of torodially compactified Type II (M-theory) and heterotic string in five and four dimensions. These quantities are parameterized by…

For N \ge 2 supergravities, BPS black hole solutions preserving four supersymmetries can be superposed linearly, leading to well defined solutions containing an arbitrary number of such BPS black holes at arbitrary positions. Being…

String theory is used to count microstates of four-dimensional extremal black holes in compactifications with $N=4$ and $N=8$ supersymmetry. The result agrees for large charges with the Bekenstein-Hawking entropy.

We propose a formulation of 11-dimensional M-theory in terms of five-branes with closed strings on their world-volume. We use this description to construct the complete spectrum of BPS states in compactifications to six and five dimensions.…

We carry out a general analysis of the representations of the superconformal algebras SU(2,2/N), OSp(8/4,R) and OSp(8^*/4) and give their realization in superspace. We present a construction of their UIR's by multiplication of the different…

With the general aim to classify BPS solutions in N=2, D=5 supergravity with hypermultiplets and vector multiplets, here we consider a family of static spacetime metrics containing black hole-like solutions, with generic hypermultiplets…

Supersymmetric closed string theories contain an infinite tower of BPS-saturated, oscillating, macroscopic strings in the perturbative spectrum. When these theories have dual formulations, this tower of states must exist nonperturbatively…

Within effective heterotic superstring theory compactified on a six-torus we derive minimum energy (supersymmetric), static, spherically symmetric solutions, which are manifestly invariant under the target space $O(6,22)$ and the…