Results in Mathematics

, Volume 20, Issue 1–2, pp 454–480 | Cite as

Limit-Point Criteria For Not Necessarily Symmetric Ordinary Differential Expressions

  • Hilbert Frentzen


A limit-point criterion for not necessarily symmetric differential expressions L of arbitrary order is proved by applying a known limit-point criterion for symmetric even-order differential expressions to (L+L)p for some positive integer p where L+ denotes the formal adjoint of L. For certain differential expressions the results obtained from the new criterion are stronger than those obtained from the original one and can even be improved by increasing p.

A.M.S. (1980) subject classification

34 B 25 


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Copyright information

© Birkhäuser Verlag, Basel 1991

Authors and Affiliations

  • Hilbert Frentzen
    • 1
  1. 1.Fachbereich 6 — MathematikUniversität Essen, Universitätsstr. 3Essen 1

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