中文
相关论文

相关论文: Covering a function on the plane by two continuous…

200 篇论文

We prove that, if f:R^n\to R satisfies Fr\'echet's functional equation and f(x_1,...,x_n) is not an ordinary algebraic polynomial in the variables x_1,...,x_n, then f is unbounded on all non-empty open set U of R^n. Furthermore, the closure…

经典分析与常微分方程 · 数学 2014-01-21 J. M. Almira , Kh. F. Abu-Helaiel

If a multiplicative function $f$ satisfies $f(a^2+b^2+c^2) = f(a)^2+f(b)^2+f(c)^2$ for all positive integers $a$, $b$, and $c$, then $f$ is an identity function.

数论 · 数学 2021-03-02 Poo-Sung Park

The r-th order nonlinearity of a Boolean function is the minimum number of elements that have to be changed in its truth table to arrive at a Boolean function of degree at most r. It is shown that the (suitably normalised) r-th order…

组合数学 · 数学 2013-08-15 Kai-Uwe Schmidt

A function on an algebra is congruence preserving if, for any congruence, it maps congruent elements to congruent elements. We show that, on a free monoid generated by at least 3 letters, a function from the free monoid into itself is…

环与代数 · 数学 2016-09-06 Patrick Cégielski , Serge Grigorieff , Irène Guessarian

0-dimensional persistent homology is known, from a computational point of view, as the easy case. Indeed, given a list of $n$ edges in non-decreasing order of filtration value, one only needs a union-find data structure to keep track of the…

计算几何 · 计算机科学 2023-12-12 Marc Glisse

This paper develops a rich theory of cardinality in the paraconsistent and paracomplete set theory $\mathrm{BZFC}$, where sets can be inconsistent ($A$ such that ``$x\in A$'' is both true and false for some $x$) or incomplete ($A$ such that…

逻辑 · 数学 2026-04-09 Hrafn Valtýr Oddsson

Inspired by recent work of A. Mardani which elaborates on the elementary fact that for any continuous function $f:\omega_1\times\mathbb{R}\to\mathbb{R}$, there is an $\alpha\in\omega_1$ such that $f(\langle\beta,x\rangle) =…

一般拓扑 · 数学 2024-09-26 Mathieu Baillif

We study one class of continuous functions $f$ defined on segment $[0,1]$ by equality $$ f(x)=\delta_{\alpha_1(x)1}+\sum^{\infty}_{k=2}\left[\delta_{\alpha_k(x)k}\prod^{k-1}_{j=1}g_{\alpha_j…

经典分析与常微分方程 · 数学 2026-03-10 S. O. Klymchuk , M. V. Pratsiovytyi

We give the definition of uniform symmetric continuity for functions defined on a nonempty subset of the real line. Then we investigate the properties of uniformly symmetrically continuous functions and compare them with those of…

经典分析与常微分方程 · 数学 2016-02-10 Tammatada Khemaratchatakumthorn , Prapanpong Pongsriiam

With the variational method introduced by J Mather, we construct a mechanical Hamiltonian system whose Alpha function has a flat F and is non-differentiable at the boundary of F. In the case of two degrees of freedom, we prove this…

动力系统 · 数学 2013-10-28 Zhang Jianlu

We study renormalizable nonlinear sigma-models in two dimensions with N=2 supersymmetry described in superspace in terms of chiral and complex linear superfields. The geometrical structure of the underlying manifold is investigated and the…

高能物理 - 理论 · 物理学 2009-10-31 Silvia Penati , Andrea Refolli , Alexander Sevrin , Daniela Zanon

A generalization of the classical Sard theorem in the plane is the following. Let $f$ be a function defined on a subset $A\subset{\mathbb R}^2$. If $f$ has modulus of continuity $\omega(r)\lesssim r^2$, then $f(A)\subset{\mathbb R}$ has…

经典分析与常微分方程 · 数学 2025-04-10 Iqra Altaf , Marianna Csörnyei

The main aim of the present paper is to introduce new classes of functions called $ \alpha $ $^m $ continuous maps and $ \alpha $ $^m $ irresolute maps. We obtain some characterizations of these classes and properties are studied.

一般拓扑 · 数学 2016-01-15 Milby Mathew , R. Parimelazhagan , S. Jafari

In this work, topological spaces are enriched by additional structures in order to give a more realistic representation of real life phenomena and computational processes and at the same time, to provide for utilization of the powerful…

一般拓扑 · 数学 2007-05-23 M. Burgin

We consider the following property: (*) For every function f from R^2 to R there are functions g_n,h_n from R to R (for n<omega) such that for all real numbers x and y, f(x,y) = sum_{n<omega} g_n(x)h_n(y). We show that, despite some…

逻辑 · 数学 2013-01-04 Andrzej Roslanowski , Saharon Shelah

The axiomatic foundations of Bentham and Rawls solutions are discussed within the broader domain of cardinal preferences. It is unveiled that both solution concepts share all four of the following axioms: Nonemptiness, Anonymity, Unanimity,…

理论经济学 · 经济学 2023-10-10 Stéphane Gonzalez , Nikolaos Pnevmatikos

Every continuous function of two or more real variables can be written as the superposition of continuous functions of one real variable along with addition.

经典分析与常微分方程 · 数学 2009-09-28 Ziqin Feng , Paul Gartside

The Tribonacci sequence $\mathbb{T}$ is the fixed point of the substitution $\sigma(a,b,c)=(ab,ac,a)$. The main result is twofold: (1) we give the explicit expressions of the numbers of distinct squares and cubes in $\mathbb{T}[1,n]$ (the…

动力系统 · 数学 2016-06-08 Huang Yuke , Wen Zhiying

It is obtained necessary and sufficient conditions of dependence on $\aleph$ coordinates for functions of several variables, each of which is a product of metrizable factors. The set of discontinuity points of such functions is…

一般拓扑 · 数学 2015-12-31 V. K. Maslyuchenko , V. V. Mykhaylyuk

It is shown that a set in product of $n$ metrizable spaces is the discontinuity points set of some separately continuous function if and only if this set can be represented as the union of a sequence of $F_{\sigma}$-sets which are locally…

一般拓扑 · 数学 2015-12-29 V. K. Maslyuchenko , V. V. Mykhaylyuk