M-branes, anti-M-branes and nonextremal black holes

An M-brane and anti-M-brane scheme is proposed to study nonextremal 4D and 5D black holes. The improved nonextremal intersecting M-brane solutions proposed here, involve two sets of harmonic functions. The constraints among the pressures are found, and new features in the M-brane and anti-M-brane picture are demonstrated, which resolve the discrepancy in the number of free parameters in the D-brane picture. In terms of the ``numbers'' of M-branes and anti-M-branes, the prefactors of the entropies are found to be model independent, and the Bekenstein-Hawking entropy assumes the duality invariant form which is consistent with the microscopic explanation of the black hole entropy.