Abstract
We develop an analog of classical oscillation theory for Sturm–Liouville operators which, rather than measuring the spectrum of one single operator, measures the difference between the spectra of two different operators.
This is done by replacing zeros of solutions of one operator by weighted zeros of Wronskians of solutions of two different operators. In particular, we show that a Sturm-type comparison theorem still holds in this situation and demonstrate how this can be used to investigate the number of eigenvalues in essential spectral gaps. Furthermore, the connection with Krein’s spectral shift function is established.
Similar content being viewed by others
References
Birman M.Sh.: On the spectrum of singular boundary value problems. AMS Translations (2) 53, 23–80 (1966)
Eastham M.S.P.: The spectral theory of periodic differential equations. Scottish Academic Press, Edinburgh (1973)
Gesztesy F., Simon B.: A short proof of Zheludev’s theorem. Trans. Am. Math. Soc. 335, 329–340 (1993)
Gesztesy F., Ünal M.: Perturbative oscillation criteria and Hardy-type inequalities. Math. Nachr. 189, 121–144 (1998)
Gesztesy F., Simon B., Teschl G.: Zeros of the Wronskian and renormalized oscillation Theory. Am. J. Math. 118, 571–594 (1996)
Gohberg I., Goldberg S., Krupnik N.: Traces and Determinants of Linear Operators. Birkhäuser, Basel (2000)
Hartman P.: Differential equations with non-oscillatory eigenfunctions. Duke Math. J. 15, 697–709 (1948)
Hartman P.: A characterization of the spectra of one-dimensional wave equations. Am. J. Math. 71, 915–920 (1949)
Hartman P., Putnam C.R.: The least cluster point of the spectrum of boundary value problems. Am. J. Math. 70, 849–855 (1948)
Kato T.: Perturbation Theory for Linear Operators. Springer, New York (1966)
Kneser A.: Untersuchungen über die reellen Nullstellen der Integrale linearer Differentialgleichungen. Math. Ann. 42, 409–435 (1893)
Khryashchev S.V.: Discrete spectrum for a periodic Schrödinger operator perturbed by a decreasing potential. Operator Theory: Adv. and Appl. 46, 109–114 (1990)
Krein M.G.: Perturbation determinants and a formula for the traces of unitary and self-adjoint operators. Sov. Math. Dokl. 3, 707–710 (1962)
Krüger H., Teschl G.: Relative oscillation theory for Sturm–Liouville operators extended. J. Funct. Anal. 254-6, 1702–1720 (2008)
Krüger, H., Teschl, G.: Effective Prüfer angles and relative oscillation criteria. J. Differ. Eqs. doi:10.1016/j.jde.2008.06.004, http://arxiv.org/abs/0709.0127v2[math.SP], 2007
Leighton W.: On self-adjoint differential equations of second order. J. London Math. Soc. 27, 37–47 (1952)
Reed M., Simon B.: Methods of Modern Mathematical Physics II. Fourier Analysis, Self-Adjointness. Academic Press, New York (1975)
Rofe-Beketov F.S.: A test for the finiteness of the number of discrete levels introduced into gaps of a continuous spectrum by perturbations of a periodic potential. Soviet Math. Dokl. 5, 689–692 (1964)
Rofe-Beketov F.S.: Spectral analysis of the Hill operator and its perturbations. FunkcionalÕnyï analiz 9, 144–155 (1977) (Russian)
Rofe-Beketov, F.S.: A generalisation of the Prüfer transformation and the discrete spectrum in gaps of the continuous one. In: Spectral Theory of Operators, Baku: Elm, 1979 (Russian), pp.146–153
Rofe-Beketov, F.S. Spectrum perturbations, the Kneser-type constants and the effective masses of zones-type potentials, Constructive Theory of Functions 84, (Sofia, 1984), Sofia: Verna, pp. 757–766
Rofe-Beketov F.S.: Kneser constants and effective masses for band potentials. Sov. Phys. Dokl. 29, 391–393 (1984)
Rofe-Beketov F.S., Kholkin A.M.: Spectral analysis of differential operators. Interplay between spectral and oscillatory properties. Hackensack, World Scientific (2005)
Schmidt K.M.: Critical coupling constants and eigenvalue asymptotics of perturbed periodic Sturm–Liouville operators. Commun. Math. Phys. 211, 465–485 (2000)
Schmidt K.M.: Relative oscillation non-oscillation criteria for perturbed periodic Dirac systems. J. Math. Anal. Appl. 246, 591–607 (2000)
Schmidt K.M.: An application of Gesztesy-Simon-Teschl oscillation theory to a problem in differential geometry. J. Math. Anal. Appl. 261, 61–71 (2001)
Simon B.: Quantum Mechanics for Hamiltonians Defined as Quadratic Forms. Princeton University Press, Princeton, NJ (1971)
Simon B.: Trace Ideals and Their Applications. 2nd ed. Providence, RI, Amer. Math. Soc., (2005)
Simon, B.: Spectral Analysis of Rank One Perturbations and Applications. Lecture notes from Vancouver Summer School in Mathematical Physics, August 10–14, 1993, CRM Proc. 8, Providence, RI: Amer. Math. Soc., 1994
Simon, B.: Sturm oscillation and comparison theorems. In: Sturm–Liouville Theory: Past and Present (eds. Amrein, W., Hinz, A., Pearson, D.), Basel: Birkhäuser, 2005, pp. 29–43
Stolz G., Weidmann J.: Approximation of isolated eigenvalues of ordinary differential operators. J. Reine und Angew. Math. 445, 31–44 (1993)
Sturm J.C.F.: Mémoire sur les équations différentielles linéaires du second ordre. J. Math. Pures Appl. 1, 106–186 (1836)
Teschl G.: Oscillation theory and renormalized oscillation theory for Jacobi operators. J. Diff. Eqs. 129, 532–558 (1996)
Teschl G.: Renormalized oscillation theory for Dirac operators. Proc. Amer. Math. Soc. 126, 1685–1695 (1998)
Teschl G.: Jacobi Operators and Completely Integrable Nonlinear Lattices Math. Surv. and Mon. 72. Providence, RI, Amer. Math. Soc., (2000)
Teschl G.: On the approximation of isolated eigenvalues of ordinary differential operators. Proc. Amer. Math. Soc. 136, 2473–2476 (2008)
Teschl, G.: Relative oscillation theory for Dirac operators. In preparation
Teschl, G.: Relative oscillation theory for Jacobi operators. In preparation.
Walter W.: Ordinary Differential Equations. Springer, New York (1998)
Weidmann J.: Zur Spektraltheorie von Sturm–Liouville–Operatoren. Math. Z. 98, 268–302 (1967)
Weidmann J.: Oszillationsmethoden für Systeme gewöhnlicher Differentialgleichungen. Math. Z. 119, 349–373 (1971)
Weidmann J.: Spectral Theory of Ordinary Differential Operators. Lecture Notes in Mathematics, 1258. Springer, Berlin (1987)
Weidmann, J.: Spectral theory of Sturm–Liouville operators; approximation by regular problems. In: Sturm–Liouville Theory: Past and Present (eds. Amrein, W., Hinz, A., Pearson, D.), Basel: Birkhäuser, 2005, pp. 29–43
Yafaev D.R.: Mathematical Scattering Theory: General Theory. Providence, RI, Amer. Math. Soc., (1992)
Zettl A.: Sturm–Liouville Theory. Providence, RI, Amer. Math. Soc., (2005)
Zheludev, V.A., Perturbation of the spectrum of the one-dimensional self-adjoint Schrödinger operator with a periodic potential. Topics in Mathematical Physics, Vol. 4, Birman, M.Sh. (ed), New York: Consultants Bureau, 1971, pp. 55–76
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by B. Simon
Research supported by the Austrian Science Fund (FWF) under Grant No. Y330.
Rights and permissions
About this article
Cite this article
Krüger, H., Teschl, G. Relative Oscillation Theory, Weighted Zeros of the Wronskian, and the Spectral Shift Function. Commun. Math. Phys. 287, 613–640 (2009). https://doi.org/10.1007/s00220-008-0600-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00220-008-0600-8