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An operator inequality and its consequences
(\\\\\\\\Phi(B))+f(\\\\\\\\Phi(C))\\\\\\\\leq \\\\\\\\Phi(f(A))+\\\\\\\\Phi(f(D)).
\\\\\\\\end{eqnarray*}
and apply it to obtain several inequalities such as the
Jensen--Mercer operator inequality and the Petrovi\\\\\\\\\\\\\\'c operator
inequality....
Operator maps of Jensen-type
Let BJ(H) denote the set of self-adjoint operators acting on a Hilbert space H with spectra contained in an open interval J. A map Φ:BJ(H)→B(H)sa is said to be of Jensen-type if (C∗AC+D∗BD)≤C∗Φ(A)C+D∗Φ(B)D for all ...
An interview with Josip E. Pečarić
While Professor J.E. Peˇcari´c and the interviewer are meeting each
other in three conferences in Iran, Hungary and Croatia, they had some conversations
concerning life, ideas and contributions of Professor ...
Operator inequalities of Jensen type
We present some generalized Jensen type operator inequalities
involving sequences of self-adjoint operators. Among other things,
we prove that if f:[0, infty) to mathbb{R} is a continuous
convex function with f(0) leq 0...
Advances in Operator Cauchy-Schwarz inequalities and their reverses
on operator inequalities, we then review some significant recent developments of the C-S inequality and its reverses for Hilbert space operators and elements of Hilbert $C^*$-modules. In particular, we pay special attention to an operator Wielandt inequality....
Some operator inequalities involving operator means and positive linear maps
Let $A$ and $B$ be two positive operators with $0 < m \\leqslant
A, B \\leqslant M$ for positive real numbers $ M, m, \\, \\sigma$
be an operator mean and $\\sigma^{*}$ be the adjoint
mean of $ ...
An operator Karamata inequality
We present an operator version of the Karamata inequality. More
precisely, we prove that if $A$ is a selfadjoint element of a unital
C^* -algebra mathscr{A} , rho is a state on mathscr{A} , the
functions ...
A generalization of the Buzano inequality
Using a $2\\\\\\\\\\\\\\\\times 2$ matrix trick, we present an inequality
involving commutators of certain Hilbert space operators as an
operator version of Buzano\\\\\\\\\\\\\\'s inequality, which is in turn ...
Riemann sums for self-adjoint operators
This paper focuses on Riemann sums for the functional calculus of bounded self-adjoint operaors. We first obtain some monotonicity properties of operator convex functions. Using these results we then refine an
operator ...
Gruss inequality for some types of positive linear maps
Assuming a unitarily invariant norm $...
|\\cdot...
|$ is given on a two-sided ideal of bounded linear operators acting on a separable Hilbert space, it induces some unitarily invariant norms $...
|\\cdot...
|$ on matrix algebras $\\mathcal{M}_n$ for all finite values of $n$ via $...
|A...
|=...
|A\\oplus 0...
|$. We show that if $\\mathscr{A}$ is a $C^*$-algebra of finite dimension
$k$ and $\\Phi: \\mathscr{A} \\to \\mathcal{M}_n$ is a unital completely
positive map, then
\\begin{equation*}
...
|\\Phi(AB)-\\Phi(A)\\Phi(B)...
| \\leq \\frac{1}{4}
...
|I_{n}...
|\\,...
|I_{kn}...
{M}_{m}$. Further we get an analogous
inequality for certain $n$-positive maps in the setting of full
matrix algebras by using some matrix tricks. We also give a Gr\\"uss
operator inequality in the setting of $C^*$-algebras of arbitrary...