English
Related papers

Related papers: Necessary and sufficient condition for compactness…

200 papers

In this paper we prove a version of the Gohberg lemma on compact Lie groups giving an estimate from below for the distance from a given operator to the set of compact operators on compact Lie groups. As a consequence, we prove several…

Functional Analysis · Mathematics 2016-04-05 Aparajita Dasgupta , Michael Ruzhansky

In this paper our aim is to extend and improve the sufficient conditions for integral operators involving the normalized forms of the generalized Bessel functions of the first kind to be univalent in the open unit disk as investigated…

Complex Variables · Mathematics 2014-08-13 H. A. Al-Kharsani , Abeer M. Al-Zahrani , S. S. Al-Hajri

Covering ill-posed problems with compact and non-compact operators regarding the degree of ill-posedness is a never ending story written by many authors in the inverse problems literature. This paper tries to add a new narrative and some…

Numerical Analysis · Mathematics 2024-11-27 Frank Werner , Bernd Hofmann

A version of the Fr\'echet-Kolmogorov theorem for the compactness of operators in weighted mixed Lebesgue spaces is proved and a corresponding compact extrapolation theory a la Rubio de Francia is developed. Several applications are…

Functional Analysis · Mathematics 2025-04-03 María J. Carro , Carlos Pérez , Rodolfo H. Torres

A revised version of the compactness criterion for families of quantum operations in the strong convergence topology (obtained previously) is presented, along with a more detailed proof and the examples showing the necessity of this…

Quantum Physics · Physics 2025-02-18 M. E. Shirokov

We give blow-up analysis for a Brezis and Merle's problem with Dirichlet and Holderian condition. Also, we derive a compactness criterion.

Analysis of PDEs · Mathematics 2018-01-23 Samy Skander Bahoura , Skander Samy

For a class of de Branges spaces containing polynomials, sufficient and necessary conditions are given for the boundedness and compactness of the Hausdorff operators under consideration. For the Paly-Wiener spaces we reduce the study of our…

Functional Analysis · Mathematics 2026-04-02 A. R. Mirotin

We continue the study of multidimensional operator multipliers initiated in [arXiv:math/0701645]. We introduce the notion of the symbol of an operator multiplier. We characterise completely compact operator multipliers in terms of their…

Operator Algebras · Mathematics 2015-02-06 K. Juschenko , R. H. Levene , I. G. Todorov , L. Turowska

We prove a wavelet $T(1)$ theorem for compactness of multilinear Calder\'{o}n-Zygmund (CZ) operators. Our approach characterizes compactness in terms of testing conditions and yields a representation theorem for compact CZ forms in terms of…

Classical Analysis and ODEs · Mathematics 2025-10-09 Anastasios Fragkos , A. Walton Green , Brett D. Wick

The ``multiple of the inclusion plus compact problem'' which was posed by T.W. Gowers in 1996 and Th. Schlumprecht in 2003, asks whether for every infinite dimensional Banach space $X$ there exists a closed subspace $Y$ of $X$ and a bounded…

Functional Analysis · Mathematics 2007-05-23 George Androulakis , Frank Sanacory

We study the boundedness of Toeplitz operators $T_\psi$ with locally integrable symbols on weighted harmonic Bergman spaces over the unit ball of $\mathbb{R}^n$. Generalizing earlier results for analytic function spaces, we derive a general…

Functional Analysis · Mathematics 2022-03-15 Raffael Hagger , Congwen Liu , Jari Taskinen , Jani A. Virtanen

Necessary and sufficient conditions for the exactness (in the algebraic sense) of certain sequences of continuous group homomorphisms are established.

Functional Analysis · Mathematics 2025-06-23 Dinamérico P. Pombo

In proving large deviation estimates, the lower bound for open sets and upper bound for compact sets are essentially local estimates. On the other hand, the upper bound for closed sets is global and compactness of space or an exponential…

Probability · Mathematics 2015-10-20 Chiranjib Mukherjee , S. R. S. Varadhan

We characterise the boundedness of a Toeplitz operator on the Bergman space with an L^1 symbol.We also prove that the compactness of a Toeplitz operator on the Bergman space with an L^1 symbol is completely determined by the boundary…

Complex Variables · Mathematics 2012-11-14 Dieudonne Agbor

In this work sufficient conditions on the order of the symbol are developed to ensure boundedness, compactness and r-nuclearity of pseudo-differential operators in $\hbar\mathbb{Z}^n$. In addition, these conditions allow us to obtain growth…

Analysis of PDEs · Mathematics 2025-05-23 Juan Pablo Lopez

We give necessary and sufficient conditions for the Hardy operator to be bounded on a rearrangement invariant quasi-Banach space in terms of its Boyd indices.

Functional Analysis · Mathematics 2008-02-03 Stephen J. Montgomery-Smith

We prove a compactness result for minimal hypersurfaces with bounded index and volume, which can be thought of as an extension of the compactness theorem of Choi-Schoen (Invent. Math. 1985) to higher dimensions.

Differential Geometry · Mathematics 2015-01-13 Ben Sharp

A full characterization of the boundedness of Laplace--Carleson embeddings on $L^\infty$ is provided, in terms of the Carleson intensity of the respective measure and of a suitable weighted Berezin transform of the measure. Moreover,…

Functional Analysis · Mathematics 2026-04-14 Birgit Jacob , Jonathan R. Partington , Sandra Pott , Eskil Rydhe , Felix L. Schwenninger

In this paper, we firstly give a matrix approach to the bases of a separable Hilbert space and then correct a mistake appearing in both review and the English translation of the Olevskii's paper. After this, we show that even a diagonal…

Functional Analysis · Mathematics 2012-03-19 Yang Cao , Geng Tian , Bingzhe Hou

In the article the necessary and sufficient conditions for a representation of Lipschitz function of more than two variables as a difference of two convex functions are formulated. An algorithm of this representation is given. The outcome…

Functional Analysis · Mathematics 2017-09-12 Igor Proudnikov
‹ Prev 1 8 9 10 Next ›