Intersecting membranes in AdS and Lovelock gravity

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 curvature AdS and dS background and consider their general intersections. This illustrates some key features which make the higher Lovelock theory different to the Einstein gravity. Lovelock terms couple hypersurfaces of different dimensionalities, extending the range of possible intersection configurations. An intersection allows for localizing matter in sub-manifolds while the bulk geometry is everywhere non-singular. An implication is that the highest number of bulk dimensions which allow a 4-dimensional sub-manifold carrying matter is 7. Also, the example of colliding membranes shows the general feature of Lovelock gravity, that at the collision event (surface) there appears (spacelike) matter, thus naturally violating the dominant energy condition.