Over the past five years, theoretical physicists have realized that black branes, generalizations of black holes, in higher spacetime dimensions play a fundamental role in string theory. Some of these correspond to lowest energy, supersymmetric BPS states. One interesting aspect of this work was understanding how spin-spin interactions between the branes arise from quantum mechanical fermionic effects. It is important and interesting to understand the interplay between these different levels of descriptions. Any viable quantum theory of gravity must predict this and give a description of the microphysical processes involved, something which is lacking in Hawking's approximation.
String theory provides one such model.
Ongoing work in this area includes generalizations of the first law of black hole thermodynamics.