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In this article, we derive a common fixed point result for a pair of single valued and set-valued mappings on a metric space having graphical structure. In this case, the set-valued map is assumed to be closed valued instead of closed and…

Functional Analysis · Mathematics 2023-01-24 Pallab Maiti , Asrifa Sultana

In this paper the weak fixed point property ($w$-FPP) and the fixed point property (FPP) in Variable Lebesgue Spaces are studied. Given $(\Omega,\Sigma,\mu)$ a $\sigma$-finite measure and $p(\cdot)$ a variable exponent function, the $w$-FPP…

Functional Analysis · Mathematics 2020-10-07 T. Domínguez-Benavides , M. Japón

On a real ($\mathbb F=\mathbb R$) or complex ($\mathbb F=\mathbb C$) analytic connected 2-manifold $M$ with empty boundary consider two vector fields $X,Y$. We say that $Y$ {\it tracks} $X$ if $[Y,X]=fX$ for some continuous function…

Dynamical Systems · Mathematics 2016-06-28 Morris W. Hirsch , F. -J. Turiel

In this paper, we first introduce and study the notion of random Chebyshev centers. Further, based on the recently developed theory of stable sets, we introduce the notion of random complete normal structure so that we can prove the two…

Functional Analysis · Mathematics 2024-08-22 Xiaohuan Mu , Qiang Tu , Tiexin Guo , Hong-Kun Xu

We show that the bar recursion operators of Spector and Kohlenbach, considered as third-order functionals acting on total arguments, are not computable in Goedel's System T plus minimization, which we show to be equivalent to a programming…

Logic in Computer Science · Computer Science 2018-04-20 John Longley

K\"onig's lemma is a fundamental result about trees with countless applications in mathematics and computer science. In contrapositive form, it states that if a tree is finitely branching and well-founded (i.e. has no infinite paths), then…

Logic in Computer Science · Computer Science 2026-02-20 Henning Urbat , Thorsten Wißmann

This paper is concerned with the open problem proposed in Ammari et. al. Commun. Math.Phys, 2013. We first investigate the existence and uniqueness of Generalized Polarization Tensors (GPTs) vanishing structures locally in both two and…

Analysis of PDEs · Mathematics 2024-12-30 Fanbo Sun , Youjun Deng

We first establish a general random Sperner lemma by presenting a completely new approach for the theory of $L^{0}$-simplicial subdivisions of $L^{0}$-simplexes. Based on this, we are able to achieve a new complete proof of the random…

Functional Analysis · Mathematics 2025-10-30 Qiang Tu , Xiaohuan Mu , Tiexin Guo , Goong Chen

We conclude from Goedel's Theorem VII of his seminal 1931 paper that every recursive function f(x_{1}, x_{2}) is representable in the first-order Peano Arithmetic PA by a formula [F(x_{1}, x_{2}, x_{3})] which is algorithmically verifiable,…

General Mathematics · Mathematics 2011-12-25 Bhupinder Singh Anand

We use a method similar to ultraproducts to study the common fixed point of a left reversible semitopological semigroup acting on a Banach space. As an application, we prove a Bruck-type theorem for nearly uniformly convex Banach spaces to…

Functional Analysis · Mathematics 2017-02-02 Fouad Naderi

We introduce the notion of feedback computable functions from $2^\omega$ to $2^\omega$, extending feedback Turing computation in analogy with the standard notion of computability for functions from $2^\omega$ to $2^\omega$. We then show…

Logic · Mathematics 2023-06-22 Nathanael L. Ackerman , Cameron E. Freer , Robert S. Lubarsky

We investigate infinitary wellfounded systems for linear logic with fixed points, with transfinite branching rules indexed by some closure ordinal $\alpha$ for fixed points. Our main result is that provability in the system for some…

Logic · Mathematics 2026-02-24 Anupam Das , Tikhon Pshenitsyn

We introduce "logically contractive mappings" nonexpansive self-maps that contract along a subsequence of iterates and prove a fixed-point theorem that extends Banach's principle. We obtain event-indexed convergence rates and, under bounded…

Functional Analysis · Mathematics 2025-08-12 Faruk Alpay , Taylan Alpay

It is well-known that deciding equivalence of logic circuits is a coNP-complete problem. As a corollary, the problem of deciding weak equivalence of reversible circuits, i.e. ignoring the ancilla bits, is also coNP-complete. The complexity…

Computational Complexity · Computer Science 2016-10-17 Stephen P. Jordan

We prove that weighted circuit satisfiability for monotone or antimonotone circuits has no fixed-parameter tractable approximation algorithm with any approximation ratio function $\rho$, unless $FPT\neq W[1]$. In particular, not having such…

Computational Complexity · Computer Science 2017-11-13 Dániel Marx

We give a counterexample to the generalized Bogomolov-Gieseker inequality for threefolds conjectured by Bayer, Macr\`i and Toda using the blow up of a point over three dimensional projective space.

Algebraic Geometry · Mathematics 2019-02-21 Benjamin Schmidt

We use fixed point theory to analyze nonnegative neural networks, which we define as neural networks that map nonnegative vectors to nonnegative vectors. We first show that nonnegative neural networks with nonnegative weights and biases can…

Machine Learning · Statistics 2024-06-18 Tomasz J. Piotrowski , Renato L. G. Cavalcante , Mateusz Gabor

The topological reconstruction problem asks how much information about a topological space can be recovered from its point-complement subspaces. If the whole space can be recovered in this way, it is called reconstructible. Our main result…

General Topology · Mathematics 2015-01-21 Max F. Pitz

In the \emph {barrier resilience} problem (introduced by Kumar {\em et al.}, Wireless Networks 2007), we are given a collection of regions of the plane, acting as obstacles, and we would like to remove the minimum number of regions so that…

Computational Complexity · Computer Science 2017-06-07 Matias Korman , Maarten Löffler , Rodrigo I. Silveira , Darren Strash

In this article, we present some fixed point theorems in partially ordered G-metric space using the concept of $(\psi,\phi)$- weak contraction which extend many existing fixed point theorems in such space. We also give some examples to show…

Functional Analysis · Mathematics 2014-03-11 Snehasish Bose , Sk Monowar Hossein