Extremal stringy black holes in equilibrium at first order in ${\alpha }^{\prime }$

Abstract

We compute the first-order ${\alpha }^{\prime }$ corrections to well-known families of heterotic multi-center black-hole solutions in five and four dimensions. The solutions can be either supersymmetric or non-supersymmetric, depending on the relative sign between two of the black-hole charges. For both cases, we find that the equilibrium of forces persists after including the ${\alpha }^{\prime }$ corrections, as the existence of multi-center solutions free of unphysical singularities shows. We analyze the possibility of black-hole fragmentation.

Abstract, introduction and conclusions rewritten with a different point of view. The multi-center black-hole solutions found and the main results remain unchanged. 42 pages, 7 figures