English
Related papers

Related papers: Fixed Point Theorem: Variants, Affine Context and …

200 papers

In this paper, we present the Brouwer-Schauder-Tychonoff fixed point theorem on locally convex spaces as the following extension and improvement: Suppose that S is a compact star-shaped subset with respect to p in S with its convexity index…

Functional Analysis · Mathematics 2026-02-11 Lixin Cheng , Chulei Liu , Wen Zhang

In this paper, we develop new affine-invariant algorithms for solving composite convex minimization problems with bounded domain. We present a general framework of Contracting-Point methods, which solve at each iteration an auxiliary…

Optimization and Control · Mathematics 2020-09-21 Nikita Doikov , Yurii Nesterov

The classical Muckenhoupt's $A_p$ condition is necessary and sufficient for the boundedness of the maximal operator $M$ on $L^p(w)$ spaces. In this paper we obtain another characterization of the $A_p$ condition. As a result, we show that…

Classical Analysis and ODEs · Mathematics 2024-09-18 Andrei K. Lerner

We study the existence of fixed points for continuous maps $f$ from an $n$-ball $X$ in $\mathbb R^n$ to $\mathbb R^n$ with $n\geq 1$. We show that $f$ has a fixed point if, for some absolute retract $Y\subset\partial X$, $f(Y)\subset X$ and…

Dynamical Systems · Mathematics 2024-04-09 Jiehua Mai , Enhui Shi , Kesong Yan , Fanping Zeng

We explore the extent to which the Fourier transform of an $L^p$ density supported on the sphere in $\mathbb{R}^n$ can have large mass on affine subspaces, placing particular emphasis on lines and hyperplanes. This involves establishing…

Classical Analysis and ODEs · Mathematics 2020-01-07 Jonathan Bennett , Shohei Nakamura

We present a general fixed point theorem which can be seen as the quintessence of the principles of proof for Banach's Fixed Point Theorem, ultrametric and certain topological fixed point theorems. It works in a minimal setting, not…

Commutative Algebra · Mathematics 2013-04-02 Katarzyna Kuhlmann , Franz-Viktor Kuhlmann

We completely describe a new domain for abstract interpretation of numerical programs. Fixpoint iteration in this domain is proved to converge to finite precise invariants for (at least) the class of stable linear recursive filters of any…

Logic in Computer Science · Computer Science 2008-07-21 Eric Goubault , Sylvie Putot

We study the fixed points of the Berezin transform in polyanalytic Fock spaces of $\mathbb{C}$. We show that an $L^p$ function, $p\in[1,+\infty]$, with respect to the Lebesgue measure is invariant under this transformation if and only if it…

Functional Analysis · Mathematics 2019-03-14 Irène Casseli

We discuss some results concerning fixed point equations in the setting of topological *-algebras of unbounded operators. In particular, an existence result is obtained for what we have called {\em weak $\tau$ strict contractions}, and some…

Mathematical Physics · Physics 2007-05-23 F. Bagarello

In this work the following energy is considered $I(u)=\int\limits_B{\frac{1}{2}|\nabla u|^2+\rho(\det\nabla u)\;dx},$ where $B\subset\mathbb{R}^2$ denotes the unit ball, $u\in W^{1,2}(B,\mathbb{R}^2),$ and…

Analysis of PDEs · Mathematics 2022-05-26 Marcel Dengler

For given $p\in\lbrack1,\infty]$ and $g\in L^{p}\mathbb{(R)}$, we establish the existence and uniqueness of solutions $f\in L^{p}(\mathbb{R)}$, to the equation \[ f(x)-af(bx)=g(x), \] where $a\in\mathbb{R}$, $b\in\mathbb{R} \setminus…

Functional Analysis · Mathematics 2015-04-07 M. F. Barnsley , B. Harding , A. Vince , P. Viswanathan

A Fourier restriction estimate is obtained for a broad class of conic surfaces by adding a weight to the usual underlying measure. The new restriction estimate exhibits a certain affine-invariance and implies the sharp $L^p-L^q$ restriction…

Classical Analysis and ODEs · Mathematics 2019-02-20 Jonathan Hickman

In this work, we prove some trace theorems for function spaces with a nonlocal character that contain the classical $W^{s,p}$ space as a subspace. The result we obtain generalizes well known trace theorems for $W^{s,p}(\Omega)$ functions…

Analysis of PDEs · Mathematics 2021-11-23 Qiang Du , Tadele Mengesha , Xiaochuan Tian

This paper presents a general study of one-dimensional differentiability for functionals defined on convex domains that are not necessarily open. The local approximation is carried out using affine functionals, as opposed to linear…

Functional Analysis · Mathematics 2025-07-04 Simone Cerreia-Vioglio , Fabio Maccheroni , Massimo Marinacci , Luigi Montrucchio , Lorenzo Stanca

We prove Banach, Newton-Raphson and Brouwer fixed point theorems in the framework of generalized smooth functions, a minimal extension of Colombeau's theory (and hence of classical distribution theory) which makes it possible to model…

Functional Analysis · Mathematics 2026-03-10 Kevin Islami , George Apaaboah , Paolo Giordano

The design of fixed point algorithms is at the heart of monotone operator theory, convex analysis, and of many modern optimization problems arising in machine learning and control. This tutorial reviews recent advances in understanding the…

Optimization and Control · Mathematics 2022-07-19 Francesco Bullo , Pedro Cisneros-Velarde , Alexander Davydov , Saber Jafarpour

Recently, Haddad, Jim\'enez, and Montenegro introduced the affine $p$-Laplace operator, $p>1$, and studied associated affine versions of the isoperimetric inequalities for the first eigenvalue of the affine $p$-Laplace operator, including…

Functional Analysis · Mathematics 2025-12-22 Dylan Langharst , Michael Roysdon

We introduce two new classes of single-valued contractions of polynomial type defined on a metric space. For the first one, called the class of polynomial contractions, we establish two fixed point theorems. Namely, we first consider the…

General Topology · Mathematics 2025-05-27 Mohamed Jleli , Cristina Maria Pacurar , Bessem Samet

There are presented certain results on extending continuous linear operators defined on spaces of E-valued continuous functions (defined on a compact Hausdorff space X) to linear operators defined on spaces of E-valued measurable functions…

Functional Analysis · Mathematics 2017-05-26 Piotr Niemiec

In the renormalisation analysis of critical phenomena in quasi-periodic systems, a fundamental role is often played by fixed points of functional recurrences of the form \begin{equation*} f_{n}(x) = \sum_{i=1}^\ell a_i(x) f_{n_i}…

Dynamical Systems · Mathematics 2013-11-12 Paul Verschueren , Ben D. Mestel