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Related papers: Lusternik--Schnirelmann theory on general spaces

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Let $\phi^t$ be a continuous flow on a metric space $X$ and $I$ be an isolated invariant set with an index pair $(N,L)$ and a Morse decomposition $\{M_i\}^n_{i=1}$. For every category $\nu$ on $N/L$, we prove that $\nu(N/L)\leq…

Dynamical Systems · Mathematics 2007-05-23 M. R. Razvan

In this paper we establish a natural definition of Lusternik-Schnirelmann category for simplicial complexes via the well known notion of contiguity. This category has the property of being homotopy invariant under strong equivalences, and…

Algebraic Topology · Mathematics 2015-03-06 D. Fernández-Ternero , E. Macías-Virgós , J. A. Vilches

We investigate conditions for the extendibility of continuous algebra homomorphisms $\phi$ from the Fourier algebra $A(F)$ of a locally compact group $F$ to the Fourier-Stieltjes algebra $B(G)$ of a locally compact group $G$ to maps between…

Operator Algebras · Mathematics 2023-02-21 M. Anoussis , G. K. Eleftherakis , A. Katavolos

We propose a new homotopy invariant for Lie groupoids which generalizes the classical Lusternik-Schnirelmann category for topological spaces. We use a bicategorical approach to develop a notion of contraction in this context. We propose a…

Algebraic Topology · Mathematics 2009-08-25 Hellen Colman

In this article we study a homotopy invariant cat(X,B,\xi) on a pair of finite CW complexes with respect to a continuous closed 1-form. This is a generalisation of a Lusternik-Schnirelmann category developed by Farber, studying the topology…

Algebraic Topology · Mathematics 2009-11-20 Tieqiang Li , Dirk Schuetz

Suppose that $S_1$ and $S_2$ are nonempty subsets of a complete metric space $(\mathcal{M},d)$ and $\phi,\psi:S_1\to S_2$ are mappings. The aim of this work is to investigate some conditions on $\phi$ and $\psi$ such that the two functions,…

General Topology · Mathematics 2022-04-19 Aman Deep , Rakesh Batra

A condition of Osserman type, called $\phi$-null Osserman condition, is introduced and studied in the context of Lorentz globally framed $f$-manifolds. An explicit example shows the naturalness of this condition in the setting of Lorentz…

Differential Geometry · Mathematics 2012-09-28 Letizia Brunetti

A criterion to determine the L-S category of a total space of a sphere-bundle over a sphere is given in terms of homotopy invariants of its characteristic map, and thus providing a complete answer to Ganea's Problem 4. As a result, we…

Algebraic Topology · Mathematics 2007-05-23 Norio Iwase

We develop Morse-Bott theory on posets, generalizing both discrete Morse-Bott theory for regular complexes and Morse theory on posets. Moreover, we prove a Lusternik-Schnirelmann theorem for general matchings on posets, in particular, for…

Algebraic Topology · Mathematics 2020-07-28 D. Fernández-Ternero , E. Macías-Virgós , D. Mosquera-Lois , J. A. Vilches

We characterise functions for the dual spaces of entire functions f such that fe^{-\phi}\in L^p(\C^n,\rho^{-2}dA), 0<p\leq 1, where \phi is a subharmonic weight and \rho^{-2} is a positive function called under certain conditions…

Complex Variables · Mathematics 2017-11-28 Jocelyn Gonessa

Let $Q_n$ be the quasi-projective subspace of the symplectic group $\mathrm{Sp}(n)$. In this short note, we prove that the subspace Lusternik-Schnirelmann category of $Q_n$ in $\mathrm{Sp}(n)$ is 2. For that, we use a quaternionic…

Algebraic Topology · Mathematics 2025-09-25 Enrique Macías-Virgós , Daniel Tanré

We prove a theorem that generalizes Schmidt's Subspace Theorem in the context of metric diophantine approximation. To do so we reformulate the Subspace theorem in the framework of homogeneous dynamics by introducing and studying a slope…

Number Theory · Mathematics 2021-02-08 Emmanuel Breuillard , Nicolas de Saxcé

Lusternik-Schnirelmann category (LS-category) of a topological space is the least integer $n$ such that there is a covering of $X$ by $n+1$ open sets, each of them being contractible in $X$. The cone length is the minimum number of…

Algebraic Topology · Mathematics 2026-05-15 Paul-Eugène Parent , Daniel Tanré

We show that both Lusternik-Schnirelmann category and topological complexity are particular cases of a more general notion, that we call homotopic distance between two maps. As a consequence, several properties of those invariants can be…

Algebraic Topology · Mathematics 2019-07-24 E. Macías-Virgós , D. Mosquera-Lois

If C=C_\phi denotes the mapping cone of an essential phantom map \phi from the suspension of the Eilenberg-Mac Lane complex K=K(Z,5) to the 4-sphere S=S^4 we derive the following properties: (1) The LS category of the product of C with any…

Algebraic Topology · Mathematics 2014-10-01 Joseph Roitberg

We prove that the homotopic distance between two maps defined on a manifold is bounded above by the sum of their subspace distances on the critical submanifol of any Morse-Bott function. This generalizes the Lusternik-Schnirelmann theorem…

Algebraic Topology · Mathematics 2021-05-28 E. Macías-Virgós , D. Mosquera-Lois , M. J. Pereira-Sáez

The simplicial LS-category of a finite abstract simplicial complex is a new invariant of the strong homotopy type, defined in purely combinatorial terms, that generalizes to arbitrary simplicial complexes the well known notion of arboricity…

Let $H$ be a real algebraic group acting equivariantly with finitely many orbits on a real algebraic manifold $X$ and a real algebraic bundle $\mathcal{E}$ on $X$. Let $\mathfrak{h}$ be the Lie algebra of $H$. Let…

Representation Theory · Mathematics 2017-11-29 Avraham Aizenbud , Dmitry Gourevitch , Bernhard Krötz , Gang Liu

We first characterize the image of the compactly supported smooth even functions under the q-Weinstein transform as a subspace of the Schwartz space. We then describe the space of smooth $L_{\alpha, q, a}^{2}$-functions whose q-Weinstein…

Functional Analysis · Mathematics 2020-05-04 Youssef Bettaibi , Hassen Ben Mohamed

Gelfand-Naimark-Stone duality provides an algebraic counterpart of compact Hausdorff spaces in the form of uniformly complete bounded archimedean $\ell$-algebras. In [4] we extended this duality to completely regular spaces. In this article…

General Topology · Mathematics 2019-05-17 G. Bezhanishvili , P. J. Morandi , B. Olberding
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