Generalized Dyson Series, Generalized Feynman Diagrams, the Feynman Integral and Feynman's Operational Calculus

Download or read book Generalized Dyson Series, Generalized Feynman Diagrams, the Feynman Integral and Feynman's Operational Calculus written by Gerald W. Johnson and published by American Mathematical Soc.. This book was released on 1986 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: The basic purpose of the paper is to construct, for the indicated integrals, series expansions in terms of finite multiple integrals of increasing multiplicity ("generalized Dyson series''). The authors study in detail the character of these expansions in the case when the measure [lowercase Greek]Eta = [lowercase Greek]Mu + [lowercase Greek]Nu contains, in addition to a continuous part [lowercase Greek]Mu, a discrete part [lowercase Greek]Nu as well. Using generalized Feynman diagrams they give a graphical description of the expansions obtained; they also describe the Banach algebra generated by the functionals under consideration and establish connections with Feynman's operational calculus.