Previous |  Up |  Next

Article

Keywords:
Sturm-Liouville operator; Friedrichs extension
Summary:
The characterization of the domain of the Friedrichs extension as a restriction of the maximal domain is well known. It depends on principal solutions. Here we establish a characterization as an extension of the minimal domain. Our proof is different and closer in spirit to the Friedrichs construction. It starts with the assumption that the minimal operator is bounded below and does not directly use oscillation theory.
References:
[1] Friedrichs, K.: Spektraltheorie halbbeschränkter Operatoren und Anwendungen auf die Spektralzerlegung von Differentialoperatoren I, II. German Math. Ann. 109 (1934), 465-487 Berichtigung ibid. 110 (1935), 777-779. MR 1512905
[2] Friedrichs, K.: Über die ausgezeichnete Randbedingung in der Spektraltheorie der halbbeschränkten gewöhnlichen Differentialoperatoren zweiter Ordnung. Math. Ann. German 112 (1936), 1-23. DOI 10.1007/BF01565401 | MR 1513033
[3] Hao, X., Sun, J., Wang, A., Zettl, A.: Characterization of domains of self-adjoint ordinary differential operators II. Result. Math. 61 (2012), 255-281. DOI 10.1007/s00025-011-0096-y | MR 2925120 | Zbl 1290.47046
[4] Hao, X., Sun, J., Zettl, A.: Real-parameter square-integrable solutions and the spectrum of differential operators. J. Math. Anal. Appl. 376 (2011), 696-712. DOI 10.1016/j.jmaa.2010.11.052 | MR 2747790 | Zbl 1210.47087
[5] Kalf, H.: A characterization of the Friedrichs extension of Sturm-Liouville operators. J. Lond. Math. Soc., II. Ser. 17 (1978), 511-521. DOI 10.1112/jlms/s2-17.3.511 | MR 0492493 | Zbl 0406.34029
[6] Littlejohn, L. L., Zettl, A.: The Legendre equation and its self-adjoint operators. Electron. J. Differ. Equ. (electronic only) 2011 (2011), 33 pages. MR 2821514
[7] Marletta, M., Zettl, A.: The Friedrichs extension of singular differential operators. J. Differ. Equations 160 (2000), 404-421. DOI 10.1006/jdeq.1999.3685 | MR 1736997 | Zbl 0954.47012
[8] Möller, M., Zettl, A.: Semi-boundedness of ordinary differential operators. J. Differ. Equations 115 (1995), 24-49. DOI 10.1006/jdeq.1995.1002 | MR 1308603 | Zbl 0817.34047
[9] Naimark, M. A.: Linear Differential Operators. Part II: Linear Differential Operators in Hilbert Space. Frederick Ungar Publishing, New York (1968). MR 0262880 | Zbl 0227.34020
[10] Niessen, H.-D., Zettl, A.: The Friedrichs extension of regular ordinary differential operators. Proc. R. Soc. Edinb., Sect. A 114 (1990), 229-236. DOI 10.1017/S0308210500024409 | MR 1055546 | Zbl 0712.34020
[11] Niessen, H.-D., Zettl, A.: Singular Sturm-Liouville problems: The Friedrichs extension and comparison of eigenvalues. Proc. Lond. Math. Soc., III. Ser. 64 (1992), 545-578. DOI 10.1112/plms/s3-64.3.545 | MR 1152997 | Zbl 0768.34015
[12] Rellich, F.: Halbbeschränkte gewöhnliche Differentialoperatoren zweiter Ordnung. Math. Ann. 122 (1950/51), German 343-368. DOI 10.1007/BF01342848 | MR 0043316
[13] Rosenberger, R.: Characterization of the Friedrichs extension of semi-bounded Sturm-Liouville operators. Fachbereich Mathematik der Technischen Hochschule Darmstadt Dissertation (1984), German. Zbl 0676.47027
[14] Wang, A., Sun, J., Zettl, A.: Characterization of domains of self-adjoint ordinary differential operators. J. Differ. Equations (2009), 246 1600-1622. MR 2488698 | Zbl 1169.47033
[15] Weidmann, J.: Linear Operators in Hilbert Spaces. Graduate Texts in Mathematics 68 Springer, Berlin (1980). MR 0566954 | Zbl 0434.47001
[16] Zettl, A.: Sturm-Liouville Theory. Mathematical Surveys and Monographs 121 American Mathematical Society, Providence (2005). MR 2170950 | Zbl 1103.34001
Partner of
EuDML logo