Results 21 to 30 of about 77,336 (61)
Endpoint Estimates for N-dimensional Hardy Operators and Their Commutators [PDF]
Sci China Math 2012, 2011 In this paper, it is proved that the higher dimensional Hardy operator is bounded from Hardy space to Lebesgue space. The endpoint estimate for the commutator generated by Hardy operator and (central) BMO function is also discussed.
arxiv +1 more source
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria MatematicaIn this paper, we present some results about the aproximation of fixed points of nonexpansive and enriched nonexpansive operators. In order to approximate the fixed points of enriched nonexpansive mappings, we use the Krasnoselskii-Mann iteration for ...
Socaciu Liviu-Ignat
doaj +1 more source
XMO and Weighted Compact Bilinear Commutators [PDF]
arXiv, 2019 To study the compactness of bilinear commutators of certain bilinear Calder\'on--Zygmund operators which include (inhomogeneous) Coifman--Meyer bilinear Fourier multipliers and bilinear pseudodifferential operators as special examples, Torres and Xue [Rev. Mat. Iberoam.
arxiv
Equivalence between estimates for quasi-commutators and commutators [PDF]
arXiv, 2017 In this short note we show that under some mild conditions on the space and the operators, an estimate for $\|Sf(A) - f(B)S\|$ needs only to be studied for invertible $S$ and $B$ equal to $A$. Thus estimates for a quasi-commutator can be derived from that for the commutator.
arxiv
arXiv, 2018 Let $ x=(x_{n})_{n} $ be a bounded complex sequence and let $M_{x} = \sup_n |x_n|$. By using a normaloid operator related to the sequence $ x=(x_{n})_{n} $, we prove that $$ \sup_{\lambda \in \mathbb{C}, |\lambda| \leq M_x} \sup_n |x_n+\lambda| = 2M_x.$$
arxiv
Multipliers on Noncommutative Orlicz Spaces [PDF]
, 2012 We establish very general criteria for the existence of multiplication operators between noncommutative Orlicz spaces $L^{\psi_0}(\tM)$ and $L^{\psi_1}(\tM)$. We then show that these criteria contain existing results, before going on to briefly look at the extent to which the theory of multipliers on Orlicz spaces differs from that of $L^p$-spaces.
arxiv +1 more source
Some generalized numerical radius inequalities for Hilbert space operators [PDF]
Sattari, Mostafa; Moslehian, Mohammad Sal; Yamazaki, Takeaki. Some
generalized numerical radius inequalities for Hilbert space operators. Linear
Algebra Appl. 470 (2015), 216--227, 2014 We generalize several inequalities involving powers of the numerical radius for product of two operators acting on a Hilbert space. For any $A, B, X\in \mathbb{B}(\mathscr{H})$ such that $A,B$ are positive, we establish some numerical radius inequalities for $A^\alpha XB^\alpha$ and $A^\alpha X B^{1-\alpha}\,\,(0 \leq \alpha \leq 1)$ and Heinz means ...
arxiv
Anticommutator Norm Formula for Projection Operators [PDF]
arXiv, 2016 We prove that for any two projection operators $f,g$ on Hilbert space, their anticommutator norm is given by the formula \[\|fg + gf\| = \|fg\| + \|fg\|^2.\] The result demonstrates an interesting contrast between the commutator and anticommutator of two projection operators on Hilbert space.
arxiv
Parallelism in Hilbert $K(\mathcal{H})$-modules [PDF]
arXiv, 2018 Let $(\mathcal{H}, [\cdot, \cdot ])$ be a Hilbert space and $K(\mathcal{H})$ be the $C^*$-algebra of compact operators on $\mathcal{H}$. In this paper, we present some characterizations of the norm-parallelism for elements of a Hilbert $K(\mathcal{H})$-module $\mathcal{E}$ by employing the minimal projections on $\mathcal{H}$.
arxiv
The operator--valued parallelism and norm-parallelism in matrices [PDF]
arXiv, 2018 Let $\mathcal{H}$ be a Hilbert space, and let $K(\mathcal{H})$ be the $C^*$-algebra of compact operators on $\mathcal{H}$. In this paper, we present some characterizations of the norm-parallelism for elements of a Hilbert $K(\mathcal{H})$-module by employing the Birkhoff--James orthogonality.
arxiv