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We propose two very simple methods, the first one with constant step sizes and the second one with self-adaptive step sizes, for finding a zero of the sum of two monotone operators in real reflexive Banach spaces. Our methods require only…

Optimization and Control · Mathematics 2022-07-12 Chinedu Izuchukwu , Simeon Reich , Yekini Shehu

The concept of adjusted sublevel set for a quasiconvex function was introduced in \cite{AuHa05} and the local existence of a norm-to-weak$^*$ upper semicontinuous base-valued submap of the normal operator associated to the adjusted sublevel…

Optimization and Control · Mathematics 2023-01-31 Marco Castellani , Massimiliano Giuli

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

We consider Banach spaces equipped with a set of strongly continuous bounded semigroups satisfying certain conditions. Using these semigroups we introduce an analog of a modulus of continuity and define analogs of Besov norms. A…

Functional Analysis · Mathematics 2023-02-28 Isaac Z. Pesenson

Let $(\mathbb{X},d,\mu)$ be a space of homogeneous type in the sense of R. R. Coifman and G. Weiss, and $X(\mathbb{X})$ a ball quasi-Banach function space on $\mathbb{X}$. In this article, the authors introduce the weak Hardy space…

Functional Analysis · Mathematics 2022-01-25 Jingsong Sun , Dachun Yang , Wen Yuan

In this paper, we survey recent progress on the theory of maximally monotone operators in general Banach space. We also extend various of the results and leave some open questions.

Functional Analysis · Mathematics 2013-07-23 Jonathan M. Borwein , Liangjin Yao

In this paper, we show how the Brezis-Browder theorem for maximally monotone multifunctions with a linear graph on a reflexive Banach space, and a consequence of it due to Yao, can be generalized to SSDB spaces.

Functional Analysis · Mathematics 2010-09-28 Stephen Simons

Many natural notions of additive and multiplicative largeness arise from results in Ramsey theory. In this paper, we explain the relationships between these notions for subsets of $\mathbb{N}$ and in more general ring-theoretic structures.…

Combinatorics · Mathematics 2024-09-11 Vitaly Bergelson , Daniel Glasscock

In the study of locally convex quasi *-algebras an important role is played by representable linear functionals; i.e., functionals which allow a GNS-construction. This paper is mainly devoted to the study of the continuity of representable…

Functional Analysis · Mathematics 2017-06-14 Maria Stella Adamo , Camillo Trapani

Monotone operators, especially in the form of subdifferential operators, are of basic importance in optimization. It is well known since Minty, Rockafellar, and Bertsekas-Eckstein that in Hilbert space, monotone operators can be understood…

Functional Analysis · Mathematics 2008-10-22 Heinz H. Bauschke , Xianfu Wang , Liangjin Yao

In this paper, we continue our study of quasihyperbolic metric in Banach spaces. The main results of the paper present a criterion for smoothness of geodesics of quasihyperbolic type metrics in Banach spaces, under a Dini type condition on…

Functional Analysis · Mathematics 2017-08-09 Antti Rasila , Jarno Talponen , Xiaohui Zhang

We introduce quasi-invariant polynomials for an arbitrary finite complex reflection group W. Unlike in the Coxeter case, the space Q_k of quasi-invariants of a given multiplicity is not, in general, an algebra but a module over the…

Representation Theory · Mathematics 2014-01-14 Yuri Berest , Oleg Chalykh

We discuss a new pseudometric on the space of all norms on a finite-dimensional vector space (or free module) $\mathbb{F}^k$, with $\mathbb{F}$ the real, complex, or quaternion numbers. This metric arises from the Lipschitz-equivalence of…

Metric Geometry · Mathematics 2018-11-01 Apoorva Khare

For a conditional quasi-greedy basis $\mathcal{B}$ in a Banach space the associated conditionality constants $k_{m}[\mathcal{B}]$ verify the estimate $k_{m}[\mathcal{B}]=\mathcal{O}(\log m)$. Answering a question raised by Temlyakov, Yang,…

Functional Analysis · Mathematics 2017-02-22 Fernando Albiac , José L. Ansorena , Przemysław Wojtaszczyk

This paper is dedicated to weighted composition semigroups on spaces of continuous functions and their subspaces. We consider semigroups induced by semiflows and semicocycles on Banach spaces $\mathcal{F}(\Omega)$ of continuous functions on…

Functional Analysis · Mathematics 2024-06-13 Karsten Kruse

We investigate some genuine Poisson geometric objects in the modular theory of an arbitrary von Neumann algebra $\mathfrak{M}$. Specifically, for any standard form realization $(\mathfrak{M},\mathcal{H},J,\mathcal{P})$, we find a canonical…

Operator Algebras · Mathematics 2026-05-29 Daniel Beltita , Anatol Odzijewicz

The paper elucidates the relationship between the density of a Banach space and possible sizes of well-separated subsets of its unit sphere. For example, it is proved that for a large enough space $X$, the unit sphere $S_X$ always contains…

Functional Analysis · Mathematics 2021-01-13 Petr Hájek , Tomasz Kania , Tommaso Russo

In this paper, first-order Sobolev-type spaces on abstract metric measure spaces are defined using the notion of (weak) upper gradients, where the summability of a function and its upper gradient is measured by the "norm" of a quasi-Banach…

Functional Analysis · Mathematics 2016-09-23 Lukáš Malý

In the present work we show that the local generalized monotonicity of a lower semicontinuous set-valued operator on some certain type of dense sets ensures the global generalized monotonicity of that operator. We achieve this goal…

Functional Analysis · Mathematics 2013-10-17 Szilárd László , Adrian Viorel

A (Hasse) diagram of a finite partially ordered set (poset) P will be called quasiplanar if for any two incomparable elements u and v, either v is on the left of all maximal chains containing u, or v is on the right of all these chains.…

Rings and Algebras · Mathematics 2013-01-01 Gábor Czédli