Abstract
In this paper we present equivalence results for several types of unbounded operator functions. A generalization of the concept equivalence after extension is introduced and used to prove equivalence and linearization for classes of unbounded operator functions. Further, we deduce methods of finding equivalences to operator matrix functions that utilizes equivalences of the entries. Finally, a method of finding equivalences and linearizations to a general case of operator matrix polynomials is presented.
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The authors gratefully acknowledge the support of the Swedish Research Council under Grant No. 621-2012-3863. We sincerely thank the reviewer for the insightful comments, which were invaluable when revising the manuscript.
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Engström, C., Torshage, A. On Equivalence and Linearization of Operator Matrix Functions with Unbounded Entries. Integr. Equ. Oper. Theory 89, 465–492 (2017). https://doi.org/10.1007/s00020-017-2415-5
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DOI: https://doi.org/10.1007/s00020-017-2415-5