The Feynman Path Integral: An Historical Slice

Efforts to give an improved mathematical meaning to Feynman’s path integral formulation of quantum mechanics started soon after its introduction and continue to this day. In the present paper, one common thread of development is followed over many years, with contributions made by various authors. The present version of this line of development involves a continuous-time regularization for a general phase space path integral and provides, in the author’s opinion at least, perhaps the optimal formulation of the path integral. The Feynman Path Integral, 1948 Much has already been written about Feynman path integrals, and, no doubt, much more will be written in the future. A comprehensive survey after more than fifty years since their introduction would be a major undertaking, and this paper is not such a survey. Rather, it is an attempt to follow one relatively narrow development regarding a special form of regularization used in the definition of path integrals. Since we deal with several different approaches, this paper does not go too deeply into any one of them; it is intended more as a conceptual overview rather than a detailed exposition. Electronic mail: