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Related papers: A Lefschetz type coincidence theorem

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We prove a Lefschetz duality result for intersection homology. Usually, this result applies to pseudomanifolds with boundary which are assumed to have a "collared neighborhood of their boundary". Our duality does not need this assumption…

Algebraic Topology · Mathematics 2011-04-21 G. Valette

We prove two general decomposition theorems for fixed-point invariants: one for the Lefschetz number and one for the Reidemeister trace. These theorems imply the familiar additivity results for these invariants. Moreover, the proofs of…

Algebraic Topology · Mathematics 2017-09-28 Kate Ponto , Michael Shulman

In classical fixed point and coincidence theory the notion of Nielsen numbers has proved to be extremely fruitful. Here we extend it to pairs (f_1, f_2) of maps between manifolds of arbitrary dimensions. This leads to estimates of the…

Algebraic Topology · Mathematics 2007-05-23 Ulrich Koschorke

For graphs F and G an F-matching in G is a subgraph of G consisting of pairwise vertex disjoint copies of F. The number of F-matchings in G is denoted by s(F,G). We show that for every fixed positive integer m and every fixed tree F, the…

Combinatorics · Mathematics 2010-06-29 Noga Alon , Simi Haber , Michael Krivelevich

For a holomorphic one-form $\mathbf{\xi}$ on a weakly 1-complete manifold $X$ with certain properties, we discussed the connectivity of the pair $(\hat{X}, F^{-1}(z))$, where $\pi : \hat{X} \to X$ is a covering map and…

Differential Geometry · Mathematics 2022-12-16 Chen Zhou

We use Morse theory to prove that the Lefschetz Hyperplane Theorem holds for compact smooth Deligne-Mumford stacks over the site of complex manifolds. For $Z \subset X$ a hyperplane section, $X$ can be obtained from $Z$ by a sequence of…

Differential Geometry · Mathematics 2010-08-06 Daniel Halpern-Leistner

Let $f_1,...,f_k:M\to N$ be maps between closed manifolds, $N(f_1,...,f_k)$ and $R(f_1,...,f_k)$ be the Nielsen and the Reideimeister coincidence numbers respectively. In this note, we relate $R(f_1,...,f_k)$ with…

Algebraic Topology · Mathematics 2020-01-22 Thaís F. M. Monis , Peter Wong

Let $f,g:X \to Y$ be continuous mappings. We say that $f$ is topologically equivalent to $g$ if there exist homeomorphisms $\Phi : X\to X$ and $\Psi: Y\to Y$ such that $\Psi\circ f\circ \Phi=g.$ Let $X,Y$ be complex smooth irreducible…

Algebraic Geometry · Mathematics 2015-02-10 Zbigniew Jelonek

For a Hausdorff space $Y$, a topological space $X$ and a map $g:X\to Y$, we present a connection between the relative sectional number of the first coordinate projection $\pi_{2,1}^Y:F(Y,2)\to Y$ with respect to $g$, and the coincidence…

Algebraic Topology · Mathematics 2026-02-06 Cesar A. Ipanaque Zapata , Felipe A. Torres Estrella

We give an approximate Menger-type theorem for when a graph $G$ contains two $X-Y$ paths $P_1$ and $P_2$ such that $P_1 \cup P_2$ is an induced subgraph of $G$. More generally, we prove that there exists a function $f(d) \in O(d)$, such…

Combinatorics · Mathematics 2024-05-24 Sandra Albrechtsen , Tony Huynh , Raphael W. Jacobs , Paul Knappe , Paul Wollan

The Lefschetz fixed point theorem and its converse have many generalizations. One of these generalizations is to endomorphisms of a space relative to a fixed subspace. In this paper we define relative Lefschetz numbers and Reidemeister…

Algebraic Topology · Mathematics 2014-10-01 Kate Ponto

We prove a Livsic type theorem for cocycles taking values in groups of diffeomorphisms of low-dimensional manifolds. The results hold without any localization assumption and in very low regularity. We also obtain a general result (in any…

Dynamical Systems · Mathematics 2014-09-16 Alejandro Kocsard , Rafael Potrie

We extend well-known results in group theory to gyrogroups, especially the isomorphism theorems. We prove that an arbitrary gyrogroup $G$ induces the gyrogroup structure on the symmetric group of $G$ so that Cayley's Theorem is obtained.…

Group Theory · Mathematics 2015-02-09 Teerapong Suksumran , Keng Wiboonton

Using Poincar\'e duality in K-theory, we state and prove a Lefschetz fixed point formula for endomorphisms of cross product C*-algebras $C_0(X)\cross G$ coming from covariant pairs. Here $G$ is assumed countable, $X$ a manifold, and…

K-Theory and Homology · Mathematics 2008-05-29 Siegfried Echterhoff , Heath Emerson , Hyun Jeong Kim

Firstly we show a generalization of the (1,1)-Lefschetz theorem for projective toric orbifolds and secondly we prove that on 2k-dimensional quasi-smooth hypersurfaces coming from quasi-smooth intersection surfaces, under the Cayley trick,…

Algebraic Geometry · Mathematics 2023-02-09 William D. Montoya

Given a Lipschitz map $f$ from a cube into a metric space, we find several equivalent conditions for $f$ to have a Lipschitz factorization through a metric tree. As an application we prove a recent conjecture of David and Schul. The…

Metric Geometry · Mathematics 2022-03-21 Behnam Esmayli , Piotr Hajłasz

We show that any ruled surface $X$ with $\chi(X) < 0$ admits infinitely many inequivalent Lefschetz pencils of fixed genus and number of base points. Our proof proceeds by building infinitely many inequivalent Lefschetz fibrations on a…

Geometric Topology · Mathematics 2026-02-11 Seraphina Eun Bi Lee , Carlos A. Serván

After introducing the different boundary geometries of rank one symmetric spaces, we state and prove Fried's theorem in the general setting of all those geometries: a closed manifold with a similarity structure is either complete or the…

Differential Geometry · Mathematics 2019-09-25 Raphaël Alexandre

Let $F$ be a smooth foliation on a closed Riemannian manifold $M$, and let $\Lambda$ be a transverse invariant measure of $F$. Suppose that $\Lambda$ is absolutely continuous with respect to the Lebesgue measure on smooth transversals. Then…

Geometric Topology · Mathematics 2008-01-31 Jesús A. Álvarez López , Yuri A. Kordyukov

We compute the trace of an endomorphism in equivariant bivariant K-theory for a compact group G in several ways: geometrically using geometric correspondences, algebraically using localisation, and as a Hattori-Stallings trace. This results…

K-Theory and Homology · Mathematics 2015-10-23 Ivo Dell'Ambrogio , Heath Emerson , Ralf Meyer