NUMERICAL RADIUS INEQUALITIES FOR PRODUCTS OF HILBERT SPACE OPERATORS

被引:9
作者
Abu-Omar, Amer [1 ]
Kittaneh, Fuad [2 ]
机构
[1] Philadelphia Univ, Dept Basic Sci & Math, Amman, Jordan
[2] Univ Jordan, Dept Math, Amman, Jordan
关键词
Numerical radius; operator norm; inequality; normal operator; self-adjoint operator; positive operator;
D O I
10.7900/jot.2013jun12.1990
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
New numerical radius inequalities for products of two Hilbert space operators are given. Some of our inequalities improve well-known ones. Among other inequalities, it is shown that if A, B is an element of B (94), then w(AB) <= (parallel to A parallel to + D-A)w(B), where D-A = inf(z is an element of C)parallel to A - zI parallel to. Moreover, w(AB) <= parallel to A parallel to w(B) + (1/2)w(AB - BA*). In particular, if AB = BA*, then w(AB) <= parallel to A parallel to w(B).
引用
收藏
页码:521 / 527
页数:7
相关论文
共 14 条
[1]   A numerical radius inequality involving the generalized Aluthge transform [J].
Abu Omar, Amer ;
Kittaneh, Fuad .
STUDIA MATHEMATICA, 2013, 216 (01) :69-75
[2]  
Abu-Omar A., ROCKY MOUNT IN PRESS
[3]  
DAVIDSON KR, 1988, MICH MATH J, V35, P261
[4]   UNITARILY-INVARIANT OPERATOR NORMS [J].
FONG, CK ;
HOLBROOK, JAR .
CANADIAN JOURNAL OF MATHEMATICS-JOURNAL CANADIEN DE MATHEMATIQUES, 1983, 35 (02) :274-299
[5]  
Gustafson K. E., 1997, NUMERICAL RANGE FIEL
[6]  
Halmos P, 1982, HILBERT SPACE PROBLE
[7]  
Hirzallah O, 2014, MATH SCAND, V114, P110
[8]   Numerical Radius Inequalities for Certain 2 x 2 Operator Matrices [J].
Hirzallah, Omar ;
Kittaneh, Fuad ;
Shebrawi, Khalid .
INTEGRAL EQUATIONS AND OPERATOR THEORY, 2011, 71 (01) :129-147
[9]   Numerical Radius Inequalities for Commutators of Hilbert Space Operators [J].
Hirzallah, Omar ;
Kittaneh, Fuad ;
Shebrawi, Khalid .
NUMERICAL FUNCTIONAL ANALYSIS AND OPTIMIZATION, 2011, 32 (07) :739-749
[10]   Theory vs. Experiment: Multiplicative Inequalities for the Numerical Radius of Commuting Matrices [J].
Holbrook, John ;
Schoch, Jean-Pierre .
TOPICS IN OPERATOR THEORY: OPERATORS, MATRICES AND ANALYTIC FUNCTIONS, VOL 1, 2010, 202 :273-+