References
Browder, F.E., On the spectral theory of elliptic partial differential operators. I. Math. Annalen 142, 22–130 (1961).
Brownell, F.H., Spectrum of the static potential Schrödinger equation over E n. Annals of Math. 54, 554–594 (1951).
Clark, C., An embedding theorem for function spaces. Pacific. J. Math. (to appear).
Courant, R., & D. Hilbert, Methods of Mathematical Physics, Vol. I. New York: Interscience 1953.
Friedrichs, K. O., Spektraltheorie halbbeschränkter Operatoren und Anwendung auf die Spektralzerlegung von Differentialoperatoren, I und II. Math. Ann. 109, 465–487 and 685–713 (1934).
Glazman, I. M., Direct methods for the qualitative spectral analysis of singular differential operators [Russian]. Moscow: Fizmatgiz 1963.
Kondrachoff, V.I., Sur certaines propriétés des fonctions de l'espace L p . Dokl. Akad. Nauk. SSSR. 48, 563–566 (1945).
Molcanov, A. M., On conditions for discreteness of the spectrum of a self-adjoint differential equation of second order [Russian]. Trudi Mosk. Mat. Obshchestva 2, 169–200 (1953).
Rellich, F., Das Eigenwertproblem von Δu+λu=0 in Halbröhren, in Essays presented to R. Courant, p. 329–344. New York: Interscience 1948.
Author information
Authors and Affiliations
Additional information
Communicated by M. M. Schiffer
This research was supported by the United States Air Force Office of Scientific Research, under Grant number AF-AFOSR 379-65.
Rights and permissions
About this article
Cite this article
Clark, C. On the continuous spectrum of a differential operator. Arch. Rational Mech. Anal. 21, 163–168 (1966). https://doi.org/10.1007/BF00266573
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00266573