Mathematische Annalen

, Volume 327, Issue 1, pp 191–201

Differentiable perturbation of unbounded operators


    • Institut für MathematikUniversität Wien
  • Peter W. Michor
    • Erwin Schrödinger Institute of Mathematical Physics

DOI: 10.1007/s00208-003-0446-5

Cite this article as:
Kriegl, A. & Michor, P. Math. Ann. (2003) 327: 191. doi:10.1007/s00208-003-0446-5


If A(t) is a C1,α-curve of unbounded self-adjoint operators with compact resolvents and common domain of definition, then the eigenvalues can be parameterized C1 in t. If A is C then the eigenvalues can be parameterized twice differentiably.

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