On positivity of spectral shift functions

Autor:	Anna Skripka
Rok vydání:	2017
Předmět:	Convex hull Numerical Analysis Algebra and Number Theory 010102 general mathematics Mathematical analysis 010103 numerical & computational mathematics Spectral shift 01 natural sciences Combinatorics Discrete Mathematics and Combinatorics Geometry and Topology 0101 mathematics Real line Mathematics
Zdroj:	Linear Algebra and its Applications. 523:118-130
ISSN:	0024-3795
DOI:	10.1016/j.laa.2017.02.026
Popis:	We show that every spectral shift function of an even order η 2 k is nonnegative outside the convex hull of the spectrum of an initial operator cvh σ ( H ) ; every spectral shift function of an odd order η 2 k − 1 is nonnegative (respectively, nonpositive) outside cvh σ ( H ) whenever a perturbation is nonnegative (respectively, nonpositive). We also derive several sufficient conditions for positivity of η 2 k and η 2 k − 1 on the whole real line.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::71443e03d37da9dc3b4c2ad1febfe014 https://doi.org/10.1016/j.laa.2017.02.026 Zobrazit plný text záznamu Full Text from ScienceDirect