We show that the double
integral of certain quadratic potentials depending on two time variables is in a
Banach algebra 𝒮 of functions on Wiener space all of whose members have an
analytic Feynman integral. Corollaries are given insuring (a) that 𝒮 contains a rather
broad class of functions involving double integrals of potentials depending on
two time parameters, and (b) the existence of the Fresnel integral for such
functions.