The Functional Measure In Quantum Field Theory

Abstract

One of the great legacies left to the physics community by Albert Einstein is the idea that physical predictions should be independent of the choice of coordinates. A natural way to ensure this is to formulate a theory in a way which is manifestly covariant. This is what is done for instance in the general theory of relativity. Today most physicists would not even contemplate founding a theory based on a preferred coordinate system or frame. The lack of a preferential frame is often exploited in calculations since, for example, derivations of certain results are often simpler if one adopts a coordinate system suitable for the symmetries of the problem. In general relativity it is often convenient to use a local orthonormal frame in which the metric tensor becomes just that for flat spacetime. One of the main purposes of this talk is to discuss how these ideas carry over into quantum field theory, particularly in relation to the functional measure.