Topics in Quantum Gravity

[摘要] We study some aspects of conformal field theory, wormhole physics and two-dimensionalrandom surfaces. Inspite of being rather different, these topics serveas examples of the issues that are involved, both at high and low energy scales,in formulating a quantum theory of gravity. In conformal field theory we showthat fusion and braiding properties can be used to determine the operator productcoefficients of the non-diagonal Wess-Zumino-Witten models. In wormhole physicswe show how Coleman's proposed probability distribution would result in wormholesdetermining the value of ^θQCD. We attempt such a calculation and find the mostprobable value of ^θQCD to be π. This hints at a potential conflict with nature.In random surfaces we explore the behaviour of conformal field theories coupled togravity and calculate some partition functions and correlation functions. Our resultsthrow some light on the transition that is believed to occur when the central chargeof the matter theory gets larger than one.

[发布机构] University:California Institute of Technology;Department:Physics, Mathematics and Astronomy

[关键词] Physics