Compactness and sequential compactness

2018 ◽  
pp. 119-150
Author(s):  
Nikos Katzourakis ◽  
Eugen Vărvărucă
Keyword(s):  
Sequential Compactness

scholarly journals On two-scale convergence and related sequential compactness topics

2006 ◽  
Vol 51 (3) ◽  
pp. 247-262 ◽  
Author(s):  
Anders Holmbom ◽  
Jeanette Silfver ◽  
Nils Svanstedt ◽  
Niklas Wellander
Keyword(s):  
Sequential Compactness

scholarly journals A New Characterization of Compact Sets in Fuzzy Number Spaces

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Huan Huang ◽  
Congxin Wu
Keyword(s):  
Fuzzy Number ◽  
Compact Sets ◽  
Sequential Compactness ◽  
Convergence Topology ◽  
Compact Subsets

We give a new characterization of compact subsets of the fuzzy number space equipped with the level convergence topology. Based on this, it is shown that compactness is equivalent to sequential compactness on the fuzzy number space endowed with the level convergence topology. Our results imply that some previous compactness criteria are wrong. A counterexample also is given to validate this judgment.

Finite regular invariant measures for Feller processes

1968 ◽  
Vol 5 (1) ◽  
pp. 203-209 ◽  
Author(s):  
V. E. Beneš
Keyword(s):  
Stochastic Process ◽  
Lyapunov Function ◽  
Invariant Measures ◽  
Sufficient Conditions ◽  
Ergodic Averages ◽  
Feller Process ◽  
The Third ◽  
Sequential Compactness ◽  
Finite Invariant Measure ◽  
Necessary And Sufficient

In the study of dynamical systems perturbed by noise, it is important to know whether the stochastic process of interest has a stationary distribution. Four necessary and sufficient conditions are formulated for the existence of a finite invariant measure for a Feller process on a σ-compact metric (state) space. These conditions link together stability notions from several fields. The first uses a Lyapunov function reminiscent of Lagrange stability in differential equations; the second depends on Prokhorov's condition for sequential compactness of measures; the third is a recurrence condition on the ergodic averages of the transition operator; and the fourth is analogous to a condition of Ulam and Oxtoby for the nonstochastic case.

scholarly journals Compactness in Metric Spaces

2016 ◽  
Vol 24 (3) ◽  
pp. 167-172
Author(s):  
Kazuhisa Nakasho ◽  
Keiko Narita ◽  
Yasunari Shidama
Keyword(s):  
Real Line ◽  
Metric Spaces ◽  
Topological Properties ◽  
The Real ◽  
The Third ◽  
Norm Space ◽  
Number Sequences ◽  
Sequential Compactness ◽  
Countable Compactness ◽  
Definition Of

Summary In this article, we mainly formalize in Mizar [2] the equivalence among a few compactness definitions of metric spaces, norm spaces, and the real line. In the first section, we formalized general topological properties of metric spaces. We discussed openness and closedness of subsets in metric spaces in terms of convergence of element sequences. In the second section, we firstly formalize the definition of sequentially compact, and then discuss the equivalence of compactness, countable compactness, sequential compactness, and totally boundedness with completeness in metric spaces. In the third section, we discuss compactness in norm spaces. We formalize the equivalence of compactness and sequential compactness in norm space. In the fourth section, we formalize topological properties of the real line in terms of convergence of real number sequences. In the last section, we formalize the equivalence of compactness and sequential compactness in the real line. These formalizations are based on [20], [5], [17], [14], and [4].

scholarly journals Evolutionary Quasi-Variational-Hemivariational Inequalities I: Existence and Optimal Control

2021 ◽  
Author(s):  
Shengda Zeng ◽  
Dumitru Motreanu ◽  
Akhtar A. Khan
Keyword(s):  
Optimal Control ◽  
Optimal Control Problem ◽  
Control Problem ◽  
Variational Problem ◽  
Existence Of Solutions ◽  
Hemivariational Inequalities ◽  
Central Idea ◽  
Monotone Map ◽  
Continuity Properties ◽  
Sequential Compactness

AbstractWe study a nonlinear evolutionary quasi–variational–hemivariational inequality (in short, (QVHVI)) involving a set-valued pseudo-monotone map. The central idea of our approach consists of introducing a parametric variational problem that defines a variational selection associated with (QVHVI). We prove the solvability of the parametric variational problem by employing a surjectivity theorem for the sum of operators, combined with Minty’s formulation and techniques from the nonsmooth analysis. Then, an existence theorem for (QVHVI) is established by using Kluge’s fixed point theorem for set-valued operators. As an application, an abstract optimal control problem for the (QVHVI) is investigated. We prove the existence of solutions for the optimal control problem and the weak sequential compactness of the solution set via the Weierstrass minimization theorem and the Kuratowski-type continuity properties.

Sequential Compactness

1997 ◽  
pp. 144-155
Author(s):  
Gerard Buskes ◽  
Arnoud van Rooij
Keyword(s):  
Sequential Compactness
Sign in / Sign up

Export Citation Format

Share Document