Some numerical radius inequalities for products of Hilbert space operators

Autor:	Baharak Moosavi, Mohsen Hosseini Shah
Rok vydání:	2019
Předmět:	symbols.namesake Pure mathematics General Mathematics Hilbert space symbols Radius Mathematics
Zdroj:	Filomat. 33:2089-2093
ISSN:	2406-0933 0354-5180
DOI:	10.2298/fil1907089h
Popis:	We prove several numerical radius inequalities for products of two Hilbert space operators. Some of our inequalities improve well-known ones. More precisely, we prove that, if A,B ? B(H) such that A is self-adjoint with ?1 = min ?i ? ?(A) (the spectrum of A) and ?2 = max ?i ? ?(A). Then ?(AB) ?||A||?(B) + (||A|| - |?1 + ?2|/2)DB where DB = inf ??C ||B - ?I||. In particular, if A > 0 and ?(A) ? [k||A||,||A||], then ?(AB) ? (2 - k)||A|| ?(B).
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::e3e03269a732ad83732900aa37acf646 https://doi.org/10.2298/fil1907089h Zobrazit plný text záznamu