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On measures of weak noncompactness [PDF]
Annali Di Matematica Pura Ed Applicata, 1988 The authors give an axiomatic definition of measures of weak noncompactness which is in some sense parallel to \textit{B. N. Sadovskij}'s definition of measures of (strong) noncompactness [see e.g. Usp. Mat. Nauk 27, No.1, 81-146 (1972; Zbl 0243.47033)]. The first explicit measure of weak noncompactness is due to \textit{F. S. de Blasi} [Bull.
Józef Banas
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Inequivalent measures of noncompactness
Annali Di Matematica Pura Ed Applicata, 2010Let \(X\) be a Banach space and \({\mathcal B}(X)\) denote the set of all bounded subsets of \(X\). We say that a map \(\beta:{\mathcal B}(X)\to [0,\infty)\) is a homogeneous measure of noncompactness on \(X\) if for all \(S,T\in{\mathcal B}(X)\): (1) \(\beta(S)= 0\) iff \(\overline S\) is compact, (2) \(\beta(S)\leq\beta(T)\) for all \(S\subset T ...
John Mallet-Paret, Roger D Nussbaum
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Measures of noncompactness of interpolated polynomials
Forum Mathematicum, 2022Abstract We study interpolation of the measure of noncompactness of homogeneous polynomials on Banach spaces. We prove that, for a large class of interpolation functors, preserving interpolation of measures of noncompactness of interpolated linear operators between Banach couples can be lifted to polynomials.
Mieczysław Mastyło, Eduardo Silva
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Measures of noncompactness in Köthe spaces
Topological Methods in Nonlinear AnalysisIn this paper we introduce some measures of noncompactness and establish estimates between them. Such estimates are helpful to apply fixed point theorems of Darbo-Sadovskiĭ type to compositions of operators. Explicit formulas for calculating these measures of noncompactness are also given, with a particular emphasis on Lebesgue and Orlicz spaces.
Jürgen Appell +4 more
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Measures of noncompactness and related properties
2018AbstractAttempts to classify properties of the ball B, or the space X, utilizing the notion of measures of noncompactness are presented. They are connected with the Kadec–Klee property. Measures of noncompactness are used to generalize the notion of uniform convexity and smoothness.
Kazimierz Goebel
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On some measures of noncompactness in the space of continuous functions
Nonlinear Analysis: Theory, Methods & Applications, 2008 We consider some quantities in the space of functions continuous on a bounded interval, which are related to monotonicity of functions. Based on those quantities we construct a few measures of noncompactness in the mentioned function space.
Józef Banas, Kishin Sadarangani
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1997
As we have seen in Chapter I, compactness plays an essential role in the proof of the Schauder fixed point theorem. However, there are some important problems where the operators are not compact.
J. M. Ayerbe Toledano +2 more
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As we have seen in Chapter I, compactness plays an essential role in the proof of the Schauder fixed point theorem. However, there are some important problems where the operators are not compact.
J. M. Ayerbe Toledano +2 more
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1992
In this chapter we consider the basic notions connected with measures of noncompactness (MNCs for brevity) and condensing (or densifying) operators. We define and study in detail the three main and most frequently used MNCs: the Hausdorff MNC χ the Kuratowski MNC α, and the MNC β.
R. R. Akhmerov +4 more
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In this chapter we consider the basic notions connected with measures of noncompactness (MNCs for brevity) and condensing (or densifying) operators. We define and study in detail the three main and most frequently used MNCs: the Hausdorff MNC χ the Kuratowski MNC α, and the MNC β.
R. R. Akhmerov +4 more
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Theorems of ascoli type involving measures of noncompactness
Nonlinear Analysis: Theory, Methods & Applications, 1981Hans-Peter Heinz
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Measure of Noncompactness and Spectral Theory
Mathematische Nachrichten, 1984Using the theory of measure of noncompactness the author has extended the results of J. Leray on the spectral theory to the case of noncompact operators in Fréchet spaces. Applying these results the author has estimated the radius of the essential spectrum of operators and has obtained some results in operator theory.
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