2024/02/29 by Jorge A. Borrego-Morell, Boris Shapiro, Borrego-Morell, Jorge A. +1 · 1 citation
#math.CA
paper · pdf · doi:10.48550/arxiv.2402.19087
Below we study a linear differential equation \MM (v(z,η))=ηMv(z,η), where η>0 is a large spectral parameter and \MM=∑k=1Mρk(z)(dk)/(dzk), M≥ 2 is a differential operator with polynomial coefficients such that the leading coefficient ρM(z) is a monic complex-valued polynomial with \dgrρM =M and other ρk(z)'s are complex-valued polynomials with \dgrρk ≤ k. We prove the Borel summability of its WKB-solutions in the Stokes regions. For M=3 under the assumption that ρM has simple zeros, we give the full description of the Stokes complex (i.e. the union of all Stokes curves) of this equation. Finally, we show that for the Euler-Cauchy equations, their WKB-solutions converge in the usual sense.