The black M2-M5 ring intersection spins

We review the blackfold description of the fully localized orthogonal M2-M5 intersection in eleven-dimensional supergravity which constitutes the direct gravitational analogue of the Howe-Lambert-West self-dual string soliton solution. We emphasize the preliminary implications of this description for the physics of the M2-M5 system and the novel research directions that it opens. This report contains several new results. As an extension of previous work we report new results on deformations of the M2-M5-KKW intersection that describe self-dual ring intersections. Extremal non-supersymmetric configurations of this type probe novel aspects of the M2-M5 system and allow us to explore further the merits and limitations of the blackfold description of black brane intersections. In particular, we provide an example of a situation where an effective description of extremal non-supersymmetric spike configurations is shown to capture correctly features of the exact solutions beyond its strict regime of validity. This observation hints at the existence of improved convergence properties in the underlying derivative expansion scheme without the necessary presence of supersymmetry.