Article
Proc. Amer. Math. Soc. 124, 1831-1840 (1996)
[DOI: 10.1090/S0002-9939-96-03299-6]
On the Double Commutation Method
Fritz Gesztesy and Gerald Teschl
We provide a complete spectral characterization of the double commutation
method for general Sturm-Liouville operators which inserts any finite number
of prescribed eigenvalues into spectral gaps of a given background operator.
Moreover, we explicitly determine the transformation operator which links the
background operator to its doubly commuted version (resulting in extensions and
considerably simplified proofs of spectral results even for the special case of
Schrödinger-type operators).
MSC91: Primary 34B24, 34L05; Secondary 34B20, 47A10
Keywords: Commutation methods, Sturm-Liouville operators, eigenvalues
Download