Lorenzo Cornalba , Miguel S. Costa , and Costas Kounnas 3 1 Instituut voor Theoretische Fysica, Universiteit van Amsterdam Valckenierstraat 65, 1018 XE Amsterdam, The Netherlands 2 Departamento de… (More)

We derive an eikonal approximation to high energy interactions in Anti-de Sitter spacetime, by generalizing a position space derivation of the eikonal amplitude in flat space. We are able to resum,… (More)

We revisit the geometry representing l collinear Schwarzschild black holes. It is seen that the black holes’ horizons are deformed by their mutual gravitational attraction. The geometry has a string… (More)

We propose a new cosmological scenario which resolves the conventional initial singularity problem. The space–time geometry has an unconventional time–like singularity on a lower dimensional… (More)

We conjecture chronology is protected in string theory due to the condensation of light winding strings near closed null curves. This condensation triggers a Hagedorn phase transition, whose… (More)

We consider the generalization to String and M-theory of the Melvin solution. These are flux p–branes which have (p + 1)–dimensional Poincaré invariance and are associated to an electric (p + 1)–form… (More)

We study intersecting D-branes in type 0 string theories and show that the Dp±brane bound states obey similar intersecting rules as the Dp-branes of the type II theories. The D5±-D1± brane system is… (More)

We give evidence in favour of a string/black hole transition in the case of BPS fundamental string states of the Heterotic string. Our analysis goes beyond the counting of degrees of freedom and… (More)

We start with BPS-saturated configurations of two (orthogonally) intersecting M-branes and use the electro-magnetic duality or dimensional reduction along a boost, in order to obtain new p-brane… (More)