Summation of asymptotic series in quantum field theory
Popov V.S., Eletskii V.L., Turbiner A.V.
A method is considered for summing perturbation-theory series with factorially increasing coefficients ak. A connection is established between the asymptotic value of ak as /Ó—»oo and the character of the singularity of the sum of the series. The limits of the region of applicability of the improved perturbation theory are obtained. The results were verified for a number of physical problems for which exact solutions are known.