Search results for "Measure of noncompactness"
showing 4 items of 14 documents
Recensione: MR3038069 Reviewed Banaś, Józef; Ben Amar, Afif Measures of noncompactness in locally convex spaces and fixed point theory for the sum of…
2013
A note on boundary conditions for nonlinear operators
2008
We investigate boundary conditions for strict-$\psi$-contractive and $\psi$-condensing operators. We derive results on the existence of eigenvectors with positive and negative eigenvalues and we obtain fixed point theorems for classes of noncompact opera\-tors.
Eigenvectors of k-psi-contractive wedge operators
2008
We present new boundary conditions under which the fixed point index of a strict-$\psi$-contractive wedge operator is zero. Then we investigate eigenvalues and corresponding eigenvectors of k-$\psi$-contractive wedge operators.
Compactness in Groups of Group-Valued Mappings
2022
We introduce the concepts of extended equimeasurability and extended uniform quasiboundedness in groups of group-valued mappings endowed with a topology that generalizes the topology of convergence in measure. Quantitative characteristics modeled on these concepts allow us to estimate the Hausdorff measure of noncompactness in such a contest. Our results extend and encompass some generalizations of Fréchet–Šmulian and Ascoli–Arzelà compactness criteria found in the literature.