Communications in Theoretical Physics
Normally Ordered and Antinormally Ordered Expansions of Some Exponential Operators in Hilbert Space
Fan Hong-Yi
Abstract
In this paper, the completeness relations of the fundamental representations in quantum mechanics, together with the "integration within orderd product" technique are exploited to derive normally ordered and antinormally ordered expansions of some exponential operators in Hilbert space. Applications of the normally ordered exponential operators to evaluating Feynman matrix element in coherent state representation are given, which seems to be a new approach.