Assuming an Einstein-Gauss-Bonnet theory of gravitation in a (D â‰¥ 5)-dimensional spacetime with boundary, we consider the problem of the boundary dynamics given the matter Lagrangian on it. Theâ€¦ (More)

Junction conditions for vacuum solutions in five-dimensional Einstein-Gauss-Bonnet gravity are studied. We focus on those cases where two spherically symmetric regions of space-time are joined inâ€¦ (More)

We consider intersecting hypersurfaces in curved spacetime with gravity governed by a class of actions which are topological invariants in lower dimensionality. Along with the Chern-Simons boundaryâ€¦ (More)

In the context of a toy model we discuss the phenomenon of colliding five-branes, with two of the extra space dimensions compacified on tori. In one of the branes (hidden world) the torus isâ€¦ (More)

We demonstrate that an impulse action ('recoil') on a D-particle embedded in a (four-dimensional) cosmological Robertson-Walker (RW) spacetime is described, in a Ïƒ-model framework, by a suitablyâ€¦ (More)

Colliding and intersecting hypersurfaces filled with matter (membranes) are studied in the Lovelock higher order curvature theory of gravity. Lovelock terms couple hypersurfaces of differentâ€¦ (More)

Colliding and intersecting thin membranes of matter are studied in the Lovelock higher order curvature theory of gravity. We restrict the study to constant curvature membranes in constant curvatureâ€¦ (More)

The situation of intersecting hypersurfaces in classical dimensionally continued Euler density gravity was introduced in our recent work [1]. We wish to simplify and demystify the calculations,â€¦ (More)

Critical String Theory is by definition an S-matrix theory. In this sense, (quantum) gravity situations where a unitary S-matrix may not be a well-defined concept, as a consequence of the existenceâ€¦ (More)

Colliding and intersecting hypersurfaces filled with matter (membranes) are studied in the Lovelock higher order curvature theory of gravity. Lovelock terms couple hypersurfaces of differentâ€¦ (More)