ABSTRACT


Quantum gravity can be Taylor expanded in powers of E^2 G, where E is the energy scale of the interactions considered, and G is Newton's constant in units where \hbar = c = 1. All terms are welldefined, except for the fact that, at every order, new, freely adjustable parameters appear. This means that gravity does not require deviations from standard quantummechanical procedures at any finite order in E^2 G. If, on the other hand, we wish a nonperturbative treatment, in cases where E^2 G >~ 1, fundamentally new approaches are needed. My consistency requirements are more stringent than what presently can be offered by superstring theory and its relatives, supergravity and Mtheory. The issue of the interpretation of Quantum Mechanics cannot be avoided. Return to Applied Math Colloquium home page 