ArticleOriginal scientific text
Title
Kneser's theorems for strong, weak and pseudo-solutions of ordinary differential equations in Banach spaces
Authors 1, 1
Affiliations
- Faculty of Mathematics and Computer Science, Adam Mickiewicz University, Matejki 48/49, 60-769 Poznań, Poland
Abstract
We investigate the structure of the set of solutions of the Cauchy problem x' = f(t,x), x(0) = x₀ in Banach spaces. If f satisfies a compactness condition expressed in terms of measures of weak noncompactness, and f is Pettis-integrable, then the set of pseudo-solutions of this problem is a continuum in , the space of all continuous functions from I to E endowed with the weak topology. Under some additional assumptions these solutions are, in fact, weak solutions or strong Carathéodory solutions, so we also obtain Kneser-type theorems for these classes of solutions.
Keywords
set of solutions, pseudo-solutions, measures of weak noncompactness, Pettis integral
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