Ordinary convergence of asymptotic series in the presence of zero points of the spectrum. (English. Russian original) Zbl 0811.47048
Mosc. Univ. Math. Bull. 42, No. 6, 41-50 (1987); translation from Vestn. Mosk. Univ., Ser. I 1987, No. 6, 33-40 (1987).
Summary: An algorithm is described which constructs regularized asymptotic series in the powers of a small parameter converging in the ordinary sense to the solution of the Cauchy problem for a singularly perturbed equation in case of a noninvertible bounded limiting operator.