A bstract We propose a general framework for the study of asymptotically flat spinning dyonic extremal black holes (eBHs) in D = 4 Einstein-Maxwell-dilaton theory. Restricting to the stringy value γ = 1 of the dilaton coupling constant, we report on the existence of a one parameter family of eBHs which are free of pathologies, provided their magnetic and electric charges are equal. An understanding of this condition is found from a study of the near horizon limit of the solutions, both perturbative closed form and numerical solutions being presented.
Blázquez-Salcedo et al. (Fri,) studied this question.