Operator Jensen’s Inequality for Operator Superquadratic Functions

Jensen’s Operator Inequality for Strongly Convex Functions

We give a Jensen’s operator inequality for strongly convex functions. As a corollary, we improve Hölder-McCarthy inequality under suitable conditions. More precisely we show that if Sp (A) ⊂ I ⊆ (1,∞), then 〈Ax, x〉 r ≤ 〈Ax, x〉 − r − r 2 (

An Operator Extension of Bohr's inequality

Rubio de Francia’s Littlewood-Paley inequality for operator-valued functions

We prove Rubio de Francia’s Littlewood-Paley inequality for arbitrary disjoint intervals in the noncommutative setting, i.e. for functions with values in noncommutative L-spaces. As applications, we get sufficient conditions in terms of q-variation for the boundedness of Schur multipliers on Schatten classes.

An Inequality for a Linear Discrete Operator Involving Convex Functions

For the functional A[ f ] = ∑k=1 ak f (zk) , we give necessary and sufficient conditions over the real numbers zk , such that, the inequality A[ f ] 0 , holds for some classes of convex functions. Then, we deduce an inequality related to Alzer’s inequality and a weighted majorization inequality.

An Operator Inequality Related to Jensen’s Inequality

For bounded non-negative operators A and B, Furuta showed 0 ≤ A ≤ B implies A r 2BA r 2 ≤ (A r 2BA r 2 ) s+r t+r (0 ≤ r, 0 ≤ s ≤ t). We will extend this as follows: 0 ≤ A ≤ B ! λ C (0 < λ < 1) implies A r 2 (λB + (1− λ)C)A r 2 ≤ {A r 2 (λB + (1 − λ)C)A r 2 } s+r t+r , where B ! λ C is a harmonic mean of B and C. The idea of the proof comes from Jensen’s inequality for an operator convex functio...