English
Related papers

Related papers: Characterizations of ultramaximally monotone opera…

200 papers

In this paper, we study the hypercyclic composition operators on weighted Banach spaces of functions defined on discrete metric spaces. We show that the only such composition operators act on the "little" spaces. We characterize the bounded…

Functional Analysis · Mathematics 2022-07-28 Robert F. Allen , Flavia Colonna , Rubén A. Martínez-Avendaño , Matthew A. Pons

We investigate the extremal properties of the unit ball of $L(X)_w^*$, the dual space of bounded linear operators defined on a Banach space $X$ equipped with the numerical radius norm. As an application of the present study, we obtain a…

Functional Analysis · Mathematics 2026-04-07 Subhadip Pal , Saikat Roy , Debmalya Sain

We introduce and study the notions of (generalized) hyperbolicity, topological stability and (uniform) topological expansivity for operators on locally convex spaces. We prove that every generalized hyperbolic operator on a locally convex…

Dynamical Systems · Mathematics 2024-10-29 Nilson C. Bernardes , Blas M. Caraballo , Udayan B. Darji , Vinícius V. Fávaro , Alfred Peris

In this paper, we first study some elementary properties of a typical positive contraction on $\ell_q$ for the Strong Operator Topology and the Strong* Operator Topology. Using these properties, we prove that a typical positive contraction…

Functional Analysis · Mathematics 2025-11-25 Valentin Gillet

Given a Banach space X and a bounded linear operator T on X, a subspace Y of X is almost invariant under T if TY is a subspace of Y+F for some finite-dimensional ``error'' F. In this paper, we study subspaces that are almost invariant under…

Functional Analysis · Mathematics 2009-09-21 Alexey I. Popov

We obtain an improved lower bound for the restricted reverse weak-type estimate of the Hardy-Littlewood maximal operator $M$. This result is applied to the $\lambda$-median maximal operator $m_{\lambda}$ acting on a Banach function space…

Classical Analysis and ODEs · Mathematics 2026-01-28 Andrei K. Lerner

In this paper, we study property $(UW_E)$ for hypercyclic and supercyclic operators. The stability of variants of Weyl type theorems under compact perturbations for Toeplitz operators on the Bergman space is also studied. We also provide…

Functional Analysis · Mathematics 2025-06-24 Simi Thomas , Thankarajan Prasad , Shery Fernandez

The notion of a firmly nonexpansive mapping is central in fixed point theory because of attractive convergence properties for iterates and the correspondence with maximal monotone operators due to Minty. In this paper, we systematically…

Functional Analysis · Mathematics 2011-01-26 Heinz H. Bauschke , Sarah M. Moffat , Xianfu Wang

Let $E$ be a Banach space, and let $J: E \to E^{*}$ denote the normalized duality mapping. In this paper, we establish an upper bound for $\|Jx - Jy\|$ in $q$-uniformly smooth Banach spaces, where the bound is expressed in terms of a…

Functional Analysis · Mathematics 2025-10-07 Changchi Huang , Jigen Peng , Yuchao Tang

The most famous open problem in Monotone Operator Theory concerns the maximal monotonicity of the sum of two maximally monotone operators provided that Rockafellar's constraint qualification holds. In this paper, we prove the maximal…

Functional Analysis · Mathematics 2012-12-19 Jonathan M. Borwein , Liangjin Yao

During the 1970s Br\'ezis and Browder presented a now classical characterization of maximal monotonicity of monotone linear relations in reflexive spaces. In this paper, we extend and refine their result to a general Banach space.

Functional Analysis · Mathematics 2011-10-27 Heinz H. Bauschke , Jonathan M. Borwein , Xianfu Wang , Liangjin Yao

Recently, Liu, Moursi and Vanderwerff have introduced the class of super strongly nonexpansive mappings as a counterpart to operators which are maximally monotone and uniformly monotone. We give a quantitative study of these notions in the…

Optimization and Control · Mathematics 2023-08-14 Andrei Sipos

We define and discuss properties of the class of unbounded operators which attain minimum modulus. We establish a relationship between this class and the class of norm attaining bounded operators and compare the properties of both. Also we…

Functional Analysis · Mathematics 2019-04-10 S. H. Kulkarni , G. Ramesh

We prove the existence of the invariant subspaces of some operators in a real Banach space. For example, linear isometries have invariant subspaces

Functional Analysis · Mathematics 2010-12-21 K. V. Storozhuk

We prove that if X is any complex separable infinite-dimensional Banach space with an unconditional Schauder decomposition, X supports an operator T which is chaotic and frequently hypercyclic. In contrast with the complex case, we observe…

Functional Analysis · Mathematics 2010-10-19 Manuel De la Rosa , Leonhard Frerick , Sophie Grivaux , Alfredo Peris

We determine the boundedness and compactness of a large class of operators, mapping from general Banach spaces of holomorphic functions into a particular type of spaces of functions determined by the growth of the functions, or the growth…

Functional Analysis · Mathematics 2017-03-16 Nina Zorboska

We obtain uniqueness theorems for harmonic and subharmonic functions of a new type. They lead to new analytic extension criteria and new conditions for stability of operator semigroups in Banach spaces with Fourier type.

Complex Variables · Mathematics 2007-05-23 A. Borichev , R. Chill , Yu. Tomilov

In this paper we obtain several extension properties for monotone and sublinear operators. The results obtained generalize those known for positive and linear operators.

Functional Analysis · Mathematics 2023-05-08 Sorin G. Gal

It is proved that a commutative algebra $A$ of operators in a reflexive real Banach space has an invariant subspace if each operator $T\in A$ satisfies the condition $$\|1- \varepsilon T^2\|_e \le 1 + o(\varepsilon) \text{ when }…

Functional Analysis · Mathematics 2016-12-20 Victor Lomonosov , Victor Shulman

Andreu et al [2] and Sadovskii [11] used representation spaces to study measures of non-compactness and spectral radii of operators on Banach lattices. In this paper, we develop representation spaces based on the nonstandard hull…

Functional Analysis · Mathematics 2007-05-23 Vladimir G. Troitsky