Mass–Angular-Momentum Inequality For Black Ring Spacetimes

The inequality m^{3}≥27π/4|J_{2}||J_{1}-J_{2}| relating total mass and angular momenta is established for (possibly dynamical) spacetimes admitting black holes of ring (S^{1}×S^{2}) topology. This inequality is shown to be sharp in the sense that it is saturated precisely for the extreme Pomeransky-Sen'kov black ring solutions. The physical significance of this inequality and its relation to new evidence of black ring instability, as well as …