BRANE-ANTIBRANE DEMOCRACY

We suggest a duality-invariant formula for the entropy and temperature of nonextreme black holes in supersymmetric string theory. The entrop y is given in terms of the duality-invariant parameter of the deviatio n from extremality and 56 SU(8) covariant-central charges. It interpol ates between the entropies of Schwarzschild solution and extremal solu tions with various amount of unbroken supersymmetries, and therefore, serves for classification of black holes in supersymmetric string theo ries. We introduce the second auxiliary 56 via an E(7) symmetric const raint. The symmetric and antisymmetric combinations of these two multi plets are related via moduli to the corresponding two fundamental repr esentations of E(7): brane and antibrane ''numbers.'' Using the CPT as well as C symmetry of the entropy formula and duality one can explain the mysterious simplicity of the nonextreme black hole area formula i n terms of branes and antibranes.