Convergent sequences of perturbative approximations for the anharmonic oscillator I. Harmonic approach
arXiv:hep-th/9507155 · doi:10.1142/S0217751X9600256X
Abstract
We present numerical evidence that a simple variational improvement of the ordinary perturbation theory of the quantum anharmonic oscillator can give a convergent sequence of approximations even in the extreme strong coupling limit, the purely anharmonic case. Some of the new techniques of this paper can be extended to renormalizable field theories.
29 pages, 12 Postscript figures available through anonymous ftp at ftp://algol.lpm.univ-montp2.fr ; replaces earlier version which could not be postscripted presumably due to lack of figures.uu file