Babich, V. M.; Levitan, B. M. The focussing problem and the asymptotic behavior of the spectral function of the Laplace-Beltrami operator. (English. Russian original) Zbl 0357.35020 Sov. Math., Dokl. 17(1976), 1414-1417 (1977); translation from Dokl. Akad. Nauk SSSR 230, 1017-1020 (1976). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 2 ReviewsCited in 6 Documents MSC: 35J05 Laplace operator, Helmholtz equation (reduced wave equation), Poisson equation 35P20 Asymptotic distributions of eigenvalues in context of PDEs 35J25 Boundary value problems for second-order elliptic equations PDFBibTeX XMLCite \textit{V. M. Babich} and \textit{B. M. Levitan}, Sov. Math., Dokl. 17, 1414--1417 (1976; Zbl 0357.35020); translation from Dokl. Akad. Nauk SSSR 230, 1017--1020 (1976)