Results 61 to 70 of about 165,963,646 (184)
Continuity of modulus of noncompact convexity for minimalizable measures of noncompactness
, 2015 We consider the modulus of noncompact convexity $Δ_{X,ϕ}(\varepsilon)$ associated with the minimalizable measure of noncompactness $ϕ$. We present some properties of this modulus, while the main result of this paper is showing that $Δ_{X,ϕ}(\varepsilon)$ is a subhomogenous and continuous function on $[0,ϕ(\bar{B}_X))$ for an arbitrary minimalizable ...
Rekić-Vuković, Amra +3 more
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Measures of noncompactness on the standard hilbert C*-module
Filomat, 2019 We define a measure of noncompactness ? on the standard Hilbert C*-module l2(A) over a unital C*-algebra, such that ?(E) = 0 if and only if E is A-precompact (i.e. it is ?-close to a finitely generated projective submodule for any ? > 0) and derive its properties.
Dragoljub Keckic, Zlatko Lazovic
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Surface subgroups for cocompact lattices of isometries of H2n$\mathbb {H}^{2n}$
Journal of Topology, Volume 19, Issue 3, September 2026.Abstract We prove the existence of surface subgroups within any cocompact lattice Γ$\Gamma$ in SO(2n,1)$\mathrm{SO}(2n,1)$ for n⩾2$n\geqslant 2$. This result addresses the cases missing from the work of Hamenstädt in 2015, who constructed surface subgroups in cocompact lattices for all other rank‐1 simple Lie groups of noncompact type.
Jeremy Kahn, Zhenghao Rao
wiley +1 more source
, 2020 In the present paper, some results on matrix mappings and Hausdorff measure of noncompactness of certain generalized Euler difference sequence spaces of fractional order are discussed.
Kadak, Ugur, Baliarsingh, P.
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Higher representation stability for ordered configuration spaces
Journal of Topology, Volume 19, Issue 3, September 2026.Abstract Using factorization homology with coefficients in twisted commutative algebras (TCAs), we prove two flavors of higher representation stability for the cohomology of (generalized) configuration spaces of a scheme/topological space X$X$. First, we provide an iterative procedure to study higher representation stability using actions coming from ...
Quoc P. Ho
wiley +1 more source
Simple homotopy theory for Fukaya categories
Journal of Topology, Volume 19, Issue 3, September 2026.Abstract We develop a categorical framework for simple homotopy theory in Fukaya categories, based on the fundamental group of the ambient symplectic manifold. When the first Chern class vanishes, we show that any isomorphism in the Fukaya category of a Weinstein manifold has trivial Whitehead torsion.
Yonghwan Kim
wiley +1 more source
Finiteness of the Hölder–Brascamp–Lieb constant revisited
Bulletin of the London Mathematical Society, Volume 58, Issue 8, August 2026.Abstract Abstract Hölder–Brascamp–Lieb inequalities have become a ubiquitous tool in Fourier analysis in recent years, due in large part to a theorem of Bennett et al. characterizing finiteness of the Hölder–Brascamp–Lieb constant. Here we provide a new characterization of a substantially different nature involving directed graphs of subspaces.
Philip T. Gressman
wiley +1 more source
Geometrical Coefficients and Measures of Noncompactness [PDF]
, 1992 This thesis studies various measures of noncompactness and some geometrical coefficients in metric or Bauach spaces. These geometrical numbers are useful in the study of measures of noncompactness, some of which are interesting quantities in fixed point ...
Zhao, Weiyu
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Positive Solutions for the Initial Value Problems of Fractional Evolution Equation
Journal of Function Spaces and Applications, 2013 This paper discusses the existence of positive solutions for the initial value problem of fractional evolution equation with noncompact semigroup , ; in a Banach space , where denotes the Caputo fractional derivative of order , is a closed linear ...
Yue Liang, Yu Ma, Xiaoyan Gao
doaj +1 more source
Semigroups of operators and measures of noncompactness
Journal of Functional Analysis, 1971 AbstractIt is observed that the perturbation class of an open semigroup in a Banach algebra is a closed two-sided ideal. Certain seminorms on the algebra of bounded operators are introduced; these seminorms induce norms on the quotient algebra modulo the ideal of compact operators.
Lebow, Arnold, Schechter, Martin
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