Related papers: Perturbative and Non-perturbative N =8 Supergravit…
We explore in detail the prospects of obtaining a four-dimensional de Sitter universe in classical supergravity models with warped and time-independent extra dimensions, presenting explicit cosmological solutions of the $(4+n)$-dimensional…
We study stability of occurrence of black holes and naked singularities that arise as a final state for a complete gravitational collapse of type I matter field in a spherically symmetric $N$ dimensional spacetime with equation of state $p…
We determine, in two independent ways, the number of BPS quantum states arising from supergravity degrees of freedom in a system with fixed total D4D0 charge. First, we count states generated by quantizing the spacetime degrees of freedom…
We derive the U-duality charge orbits, as well as the related moduli spaces, of "large" and "small" extremal black holes in non-maximal ungauged Maxwell-Einstein supergravities with symmetric scalar manifolds in d=5 space-time dimensions.…
We present the most general family of stationary point-like solutions of pure N=4, d=4 Supergravity characterized by completely independent electric and magnetic charges, mass, angular momentum and NUT charge plus the asymptotic values of…
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 present the asymptotically AdS solutions of Gauss-Bonnet gravity with hyperbolic horizon in the presence of a non-Abelian Yang-Mills field with the gauge semisimple group $So(n(n-1)/2-1,1)$. We investigate the properties of these…
An internal singularity of a string four-dimensional black hole with second order curvature corrections is discussed. A restriction to a minimal size of a neutral black hole is obtained in the frame of the model considered. Vacuum…
We compare the logarithm of the degeneracy of BPS saturated elementary string states and the string modified Bekenstein-Hawking entropy of the corresponding black holes in N=2 supersymmetric heterotic string compactification to four…
We find a new non BPS solution in $N=2$ $D=4$ gauged supergravity coupled to $U(1)$ gauge fields and matter. It consists in a closed universe with two extremal black holes of equal size, surrounding two singularities. They have opposite…
We obtain new non-extremal rotating black hole solutions in maximal five-dimensional gauged supergravity. They are characterised by five parameters, associated with the mass, the two angular momenta, and two independently-specifiable charge…
Using the general results on the classification of timelike supersymmetric solutions of all 4-dimensional N >1 supergravity theories, we show how to construct all the supersymmetric (single- and multi-) black-hole solutions of N=8…
In this paper we pursue the study of linear perturbations around a Schwarzschild black hole in a generalized Einstein-Cartan theory of gravity, called torsion bigravity. This theory contains both massless and massive spin-2 excitations.…
Non-trivial gravitational saddles have played a key role in the island proposal for the black hole information paradox. It is worth asking if non-trivial saddles exist in microscopic descriptions of black holes. We show this to be the case…
The effective action of $N=2$, $d=4$ supergravity is shown to acquire no quantum corrections in background metrics admitting super-covariantly constant spinors. In particular, these metrics include the Robinson-Bertotti metric (product of…
We examine the conjecture for the complete monotonicity of certain curvature invariants for quantum black holes. In this note, we study a class of quantum regular black holes that are static, spherically symmetric, and characterized only by…
We review some properties of N=8 gauged supergravity in four dimensions with modified, but AdS invariant boundary conditions on the m^2=-2 scalars. There is a one-parameter class of asymptotic conditions on these fields and the metric…
By choosing a particular, String Theory inspired, Special K\"ahler manifold, we are able to find a N=2 four-dimensional ungauged Supergravity model that contains supersymmetric black hole solutions that violate the folk uniqueness theorems…
We construct new non-extremal rotating black hole solutions in SO(6) gauged five-dimensional supergravity. Our solutions are the first such examples in which the two rotation parameters are independently specifiable, rather than being set…
We construct non-BPS regular and black hole solutions of N=4 SU(N) supersymmetric Yang-Mills theory coupled to Einstein gravity. Our numerical studies reveal a number of interesting phenomena when the gravitational constant…