This is a preview of subscription content, log in via an institution to check access.
Literature Cited
A. G. Brusentsev and F. S. Rofe-Beketov, "Self-adjointness conditions for strongly elliptic systems of arbitrary order," Mat. Sb.,95, 108–130 (1974).
L. Hörmander, "The spectral function of an elliptic operator," Acta Math.,121, Nos. 3–4, 193–218 (1968).
M. A. Naimark, Linear Differential Operators [in Russian], Nauka, Moscow (1969).
I. M. Glazman, Direct Methods of Qualitative Spectral Analysis for Singular Differential Operators [in Russian], Fizmatgiz, Moscow (1963).
M. V. Fedoryuk, "Asymptotic methods in the theory of one-dimensional singular differential operators," Tr. Mosk. Mat. O-va,15, 296–345 (1965).
S. P. Novikov, "Periodic problem for the Korteweg-de Vries equation. I," Funkts. Anal. Prilozhen.,8, No. 3, 54–66 (1974).
M. A. Shubin, "Almost periodic elliptic operators and von Neumann algebras," Funkts. Anal. Prilozhen.,9, No. 1, 89–90 (1975).
D. R. Yafaev, "The spectrum of a perturbed polyharmonic operator. II," Probl. Mat. Fiz.,6, 142–148 (1973).
I. M. Gel'fand and L. A. Dikii, "Asymptotic behavior of the resolvent of Sturm—Liouville equations and the algebra of the Korteweg—de Vries equations," Usp. Mat. Nauk,30, No. 5, 67–100 (1975).
P. Hartman and C. R. Putnam, "The gaps in the essential spectra of wave equations," Am. J. Math.,72, 849–862 (1950).
M. Eastham, "Asymptotic estimates for the lengths of the gaps in the essential spectra of self-adjoint differential operators," Proc. Roy. Soc. Edinburgh,74A, 239–252 (1976).
Additional information
All-Union Scientific-Research Institute of Economics for the Gas Industry. Translated from Funktsional'nyi i Ego Prilozheniya, Vol. 11, No. 1, pp. 43–54, January–March, 1977.
Rights and permissions
About this article
Cite this article
Feigin, V.I. The continuous spectrum of differential operators. Funct Anal Its Appl 11, 35–44 (1977). https://doi.org/10.1007/BF01135530
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01135530