Charged black holes in generalized dilaton-axion gravity
  We study generic Einstein-Maxwell-Kalb-Ramond-dilaton actions, and derive conditions under which they give rise to static, spherically symmetric black hole solutions. We obtain new asymptotically flat and non-flat black hole solutions which are in general electrically and magnetically charged. They have positive definite and finite quasi-local masses. Existing non-rotating black hole solutions (including those appearing in low energy string theory) are recovered in special limits. 
Sourav Sur (IOP, Bhubaneswar), Saurya Das (U. Lethbridge) and Soumitra   SenGupta (IACS, Kolkata)