Some generalizations of numerical radius inequalities
for Hilbert space operators
Chaojun Yang
ABSTRACT: In this article, we generalize several upper and lower bounds of the numerical radius inequalities for
Hilbert space operators. In particular, we show that if A ∈ B( ) with the Cartesian decomposition A = B + iC and f is an increasing concave function, then f (ω(A)) ≥ 1/2|| ƒ(|B+C|)+ ƒ(|B-C|). Patek Philippe replica is on sale. This is a complementary result of El-Haddad and Kittaneh [Studia Math 182 (2007):133–140].