Enclosure of the Numerical Range and Resolvent Estimates of Non-selfadjoint Operator Functions

Autor:	Torshage, Axel
Rok vydání:	2017
Předmět:	Mathematics - Functional Analysis 47J10 47A56 47A12
Druh dokumentu:	Working Paper
Popis:	In this paper we discuss the relationship between the numerical range of an extensive class of unbounded operator functions and the joint numerical range of the operator coefficients. Furthermore, we derive methods on how to find estimates of the joint numerical range. Those estimates are used to obtain explicitly computable enclosures of the numerical range of the operator function and resolvent estimates. The enclosure and upper estimate of the norm of the resolvent are optimal given the estimate of the joint numerical range. Comment: 27 pages, 4 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1711.11337 Zobrazit plný text záznamu View this record from Arxiv