Functional Integration; Path Integrals

Abstract

Definitions Functional integral is, by definition, an integral over a space of functions. The functions are the variables of integration. When the variables are paths, the functional integral is usually called a "path integral". For example, let x be a path parameter-ized by time t ∈ T , taking its values in a D-dimensional manifold M D , i.e. x : T → M D by t → x(t), (1) a sum over all paths x is a path integral. To compute a path integral X