Arnold Lagrangian singularity in the asymptotics of the solution of a model two-dimensional Helmholtz equation with a localized right-hand side. (English. Russian original) Zbl 1533.35069
Theor. Math. Phys. 218, No. 1, 19-40 (2024); translation from Teor. Mat. Fiz. 218, No. 1, 23-47 (2024).