Universal Counting of Black Hole Entropy by Strings on the Stretched Horizon

We show that the entropy of any black object in any dimension can be understood as the entropy of a highly excited string on the stretched horizon. The string has a gravitationally renormalized tension due to the large redshift near the horizon. The Hawking temperature is given by the Hagedorn temperature of the string. As examples, we consider black holes with one (black p-branes) or two charges, Reissner-Nordstrom black holes and the BTZ black hole in addition to Schwarzschild black holes. We show that the vanishing and nonvanishing extremal entropies can be obtained as smooth limits of the near-extreme cases.Comment: 21 pages in phyzzx.tex, numerous minor changes, dyonic string added as an example, one reference adde

M(atrix) Black Holes in Five Dimensions

We examine five dimensional extreme black holes with three charges in the matrix model. We build configurations of the 5+1 super Yang-Mills theory which correspond to black holes with transverse momentum charge. We calculate their mass and entropy from the super Yang-Mills theory and find that they match the semi-classical black hole results. We extend our results to nonextreme black holes in the dilute gas approximation.Comment: 20 pages in phyzzx.tex, three references adde

Supergravity on AdS4/7×S7/4AdS_{4/7} \times S^{7/4} and M Branes

We calculate the dimensions of operators in three and six dimensional superconformal field theories by using the duality between these theories at large N and D=11 supergravity on $AdS_{4/7} \times S^{7/4}$. We find that for the duality relations to work the Kaluza--Klein masses given in the supergravity literature must be rescaled and/or shifted.Comment: 10 pages on phyzzx.tex, typo (in eq. (20)) and TeX corrections, some Comments adde