English
Related papers

Related papers: Quasi-Nilpotent Operators on Locally Convex Spaces

200 papers

Motivated by the equivalent definition of a continuous operator between Banach spaces in terms of weakly null nets, we introduce two types of continuous operators between Banach lattices using unbounded absolute weak convergence. We…

Functional Analysis · Mathematics 2020-04-07 Omid Zabeti

This paper is focused on some properties of paramonotone operators on Banach spaces and their application to certain feasibility problems for convex sets in a Hilbert space and convex systems in the Euclidean space. In particular, it shows…

Optimization and Control · Mathematics 2023-07-04 J. Camacho , M. J. Cánovas , J. E. Martínez-Legaz , J. Parra

We show that there exist infinite-dimensional extremely non-complex Banach spaces, i.e. spaces $X$ such that the norm equality $\|Id + T^2\|=1 + \|T^2\|$ holds for every bounded linear operator $T:X\longrightarrow X$. This answers in the…

Functional Analysis · Mathematics 2008-11-26 Piotr Koszmider , Miguel Martin , Javier Meri

In this brief note we describe relations between the well known notion of a relatively bounded operator and the operator E-norms considered in [arXiv:1806.05668]. We show that the set of all $\sqrt{G}$-bounded operators equipped with the…

Functional Analysis · Mathematics 2018-11-27 M. E. Shirokov

We study order-to-weak continuous operators from an ordered Banach space to a normed space. It is proved that under rather mild conditions every order-to-weak continuous operator is bounded.

Functional Analysis · Mathematics 2026-03-12 Eduard Emelyanov

Motivated by the recent developments of pseudo-Hermitian quantum mechanics, we analyze the structure generated by unbounded metric operators in a Hilbert space. To that effect, we consider the notions of similarity and quasi-similarity…

Mathematical Physics · Physics 2016-10-24 Jean-Pierre Antoine , Camillo Trapani

In this paper, we study the existence of the random approximations and fixed points for random almost lower semicontinuous operators defined on finite dimensional Banach spaces, which in addition, are condensing or 1-set-contractive. Our…

Probability · Mathematics 2015-07-13 Monica Patriche

In this note, we show that the Hausdorff operator $H_{\Phi}$ is unbounded on a large family of Quasi-Banach spaces, unless $H_{\Phi}$ is a zero operator.

Classical Analysis and ODEs · Mathematics 2021-12-01 Weichao Guo , Jianmiao Ruan , Guoping Zhao

We extend the concept of average expansivity for operators on Banach spaces to operators on arbitrary locally convex spaces. We obtain complete characterizations of the average expansive weighted shifts on Fr\'echet sequence spaces.…

Functional Analysis · Mathematics 2026-03-10 Nilson C. Bernardes , Félix Martínez-Giménez , Francisco Rodenas

In this paper we present (quasi-)norm equivalence on a vector-valued function space $L^p_A(l^q)$ and extend the equivalence to $p=\infty$ and $0<q<\infty$ in the scale of Triebel-Lizorkin space, motivated by Fraizer-Jawerth. By applying the…

Classical Analysis and ODEs · Mathematics 2021-03-16 Bae Jun Park

Our goal in this paper is to extend the theory of quasi-exactly solvable Schrodinger operators beyond the Lie-algebraic class. Let $\cP_n$ be the space of n-th degree polynomials in one variable. We first analyze "exceptional polynomial…

Exactly Solvable and Integrable Systems · Physics 2013-06-20 David Gomez-Ullate , Niky Kamran , Robert Milson

In this paper we study a class of quasi--variational--hemi\-va\-ria\-tio\-nal inequalities in reflexive Banach spaces. The inequalities contain a convex potential, a locally Lipschitz superpotential, and a solution-dependent set of…

Dynamical Systems · Mathematics 2023-09-12 S. Migorski , JC. Yao , SD. Zeng

In this paper we study some geometric properties like parallelism, orthogonality and semi-rotundity in the space of bounded linear operators. We completely characterize parallelism of two compact linear operators between normed linear…

Functional Analysis · Mathematics 2024-08-13 Arpita Mal , Debmalya Sain , Kallol Paul

In this bachelor's thesis we introduce three quantities for linear and bounded operators on quasi-Banach spaces which are entropy numbers, approximation numbers and Kolmogorov numbers. At first we establish the three quantities with some…

Functional Analysis · Mathematics 2025-08-12 Marcus Gerhold

Bonet, Frerick, Peris and Wengenroth constructed a hypercyclic operator on the locally convex direct sum of countably many copies of the Banach space $\ell_1$. We extend this result. In particular, we show that there is a hypercyclic…

Functional Analysis · Mathematics 2014-02-26 Stanislav Shkarin

We present many examples of Banach spaces of linear operators and homogeneous polynomials without the approximation property, thus improving results of Dineen and Mujica [11] and Godefroy and Saphar [13].

Functional Analysis · Mathematics 2016-03-18 Sergio A. Pérez

The purpose of this paper is to investigate the stationary dense operators and their connection to distribution semigroups and abstract Cauchy problem in sequentially complete spaces.

Functional Analysis · Mathematics 2024-08-21 Marko Kostić , Stevan Pilipović , Daniel Velinov

In this paper, we investigate the boundedness of composition operators defined on a quasi-Banach space continuously included in the space of smooth functions on a manifold. We prove that the boundedness of a composition operator strongly…

Functional Analysis · Mathematics 2023-05-04 Isao Ishikawa

We prove that, any problem of minimization of proper lower semicontinuous function defined on a normal Hausdorff space, is canonically equivalent to a problem of minimization of a proper weak * lower semicontinuous convex function defined…

Functional Analysis · Mathematics 2017-05-24 Mohammed Bachir

A quasi-Hermitian operator is an operator that is similar to its adjoint in some sense, via a metric operator, i.e., a strictly positive self-adjoint operator. Whereas those metric operators are in general assumed to be bounded, we analyze…

Mathematical Physics · Physics 2016-10-24 Jean-Pierre Antoine , Camillo Trapani