Euler classes of vector bundles over manifolds

2021 ◽  
Vol 71 (1) ◽  
pp. 199-210
Author(s):  
Aniruddha C. Naolekar
Keyword(s):  
Vector Bundle ◽  
Vector Bundles ◽  
Euler Class ◽  
Homology Sphere ◽  
Rational Homology ◽  
Rational Homology Sphere ◽  
Orientable Manifolds

Abstract Let 𝓔 k denote the set of diffeomorphism classes of closed connected smooth k-manifolds X with the property that for any oriented vector bundle α over X, the Euler class e(α) = 0. We show that if X ∈ 𝓔2n+1 is orientable, then X is a rational homology sphere and π 1(X) is perfect. We also show that 𝓔8 = ∅ and derive additional cohomlogical restrictions on orientable manifolds in 𝓔 k .

IWASAWA TYPE FORMULA FOR COVERS OF A LINK IN A RATIONAL HOMOLOGY SPHERE

2008 ◽  
Vol 17 (10) ◽  
pp. 1199-1221 ◽  
Author(s):  
TERUHISA KADOKAMI ◽  
YASUSHI MIZUSAWA
Keyword(s):  
Number Field ◽  
Class Number ◽  
Homology Sphere ◽  
Rational Homology ◽  
Homology Groups ◽  
Cyclic Covers ◽  
Class Number Formula ◽  
Number Formula ◽  
Iwasawa Invariants ◽  
Rational Homology Sphere

Based on the analogy between links and primes, we present an analogue of the Iwasawa's class number formula in a Zp-extension for the p-homology groups of pn-fold cyclic covers of a link in a rational homology 3-sphere. We also describe the associated Iwasawa invariants precisely for some examples and discuss analogies with the number field case.

Strongly-cyclic branched coverings and the Alexander polynomial of knots in rational homology spheres

2007 ◽  
Vol 142 (2) ◽  
pp. 259-268 ◽  
Author(s):  
YUYA KODA
Keyword(s):  
Fundamental Group ◽  
Homology Group ◽  
Alexander Polynomial ◽  
Homology Sphere ◽  
Cyclic Covering ◽  
Rational Homology ◽  
Branched Coverings ◽  
Branched Covering ◽  
Rational Homology Spheres ◽  
Rational Homology Sphere

AbstractLet K be a knot in a rational homology sphere M. In this paper we correlate the Alexander polynomial of K with a g-word cyclic presentation for the fundamental group of the strongly-cyclic covering of M branched over K. We also give a formula for the order of the first homology group of the strongly-cyclic branched covering.

scholarly journals ON RATIONAL CUSPIDAL PROJECTIVE PLANE CURVES

2005 ◽  
Vol 92 (1) ◽  
pp. 99-138 ◽  
Author(s):  
J. FERNÁNDEZ DE BOBADILLA ◽  
I. LUENGO-VELASCO ◽  
A. MELLE-HERNÁNDEZ ◽  
A. NÉMETHI
Keyword(s):  
Singular Point ◽  
Projective Plane ◽  
Plane Curve ◽  
Topological Type ◽  
Homology Sphere ◽  
Plane Curves ◽  
Curve Singularity ◽  
Witten Invariant ◽  
Rational Homology ◽  
Rational Homology Sphere

In 2002, L. Nicolaescu and the fourth author formulated a very general conjecture which relates the geometric genus of a Gorenstein surface singularity with rational homology sphere link with the Seiberg--Witten invariant (or one of its candidates) of the link. Recently, the last three authors found some counterexamples using superisolated singularities. The theory of superisolated hypersurface singularities with rational homology sphere link is equivalent with the theory of rational cuspidal projective plane curves. In the case when the corresponding curve has only one singular point one knows no counterexample. In fact, in this case the above Seiberg--Witten conjecture led us to a very interesting and deep set of `compatibility properties' of these curves (generalising the Seiberg--Witten invariant conjecture, but sitting deeply in algebraic geometry) which seems to generalise some other famous conjectures and properties as well (for example, the Noether--Nagata or the log Bogomolov--Miyaoka--Yau inequalities). Namely, we provide a set of `compatibility conditions' which conjecturally is satisfied by a local embedded topological type of a germ of plane curve singularity and an integer $d$ if and only if the germ can be realized as the unique singular point of a rational unicuspidal projective plane curve of degree $d$. The conjectured compatibility properties have a weaker version too, valid for any rational cuspidal curve with more than one singular point. The goal of the present article is to formulate these conjectured properties, and to verify them in all the situations when the logarithmic Kodaira dimension of the complement of the corresponding plane curves is strictly less than 2.

scholarly journals Vector Fields and Genus in Dimension 3

2020 ◽  
Author(s):  
Pierre Dehornoy ◽  
Ana Rechtman
Keyword(s):  
Vector Field ◽  
Invariant Measure ◽  
Euler Characteristic ◽  
Boundary Data ◽  
Vector Fields ◽  
Homology Sphere ◽  
Rational Homology ◽  
Rational Homology Sphere

Abstract Given a vector field on a 3D rational homology sphere, we give a formula for the Euler characteristic of its transverse surfaces, in terms of boundary data only. This provides a formula for the genus of a transverse surface, and in particular, of a Birkhoff section. As an application, we show that for a right-handed flow with an ergodic invariant measure, the genus is an asymptotic invariant of order 2 proportional to helicity.

scholarly journals SEIBERG–WITTEN INVARIANTS OF RATIONAL HOMOLOGY 3-SPHERES

2004 ◽  
Vol 06 (06) ◽  
pp. 833-866 ◽  
Author(s):  
LIVIU I. NICOLAESCU
Keyword(s):  
Homology Sphere ◽  
Rational Homology ◽  
Turaev Torsion ◽  
Rational Homology Sphere

We prove that the Seiberg–Witten invariants of a rational homology sphere are determined by the Casson–Walker invariant and the Reidemeister–Turaev torsion.

scholarly journals Entropy in uniformly quasiregular dynamics

2020 ◽  
pp. 1-31
Author(s):  
ILMARI KANGASNIEMI ◽  
YÛSUKE OKUYAMA ◽  
PEKKA PANKKA ◽  
TUOMAS SAHLSTEN
Keyword(s):  
Topological Entropy ◽  
Homology Sphere ◽  
Rational Homology ◽  
Rational Homology Sphere

Let $M$ be a closed, oriented, and connected Riemannian $n$ -manifold, for $n\geq 2$ , which is not a rational homology sphere. We show that, for a non-constant and non-injective uniformly quasiregular self-map $f:M\rightarrow M$ , the topological entropy $h(f)$ is $\log \deg f$ . This proves Shub’s entropy conjecture in this case.

scholarly journals Anosov diffeomorphisms of products I. Negative curvature and rational homology spheres

2019 ◽  
Vol 41 (2) ◽  
pp. 553-569 ◽  
Author(s):  
CHRISTOFOROS NEOFYTIDIS
Keyword(s):  
Homology Sphere ◽  
Homotopy Groups ◽  
Rational Homology ◽  
Simplicial Volume ◽  
Anosov Diffeomorphisms ◽  
Curved Manifolds ◽  
Negatively Curved ◽  
Rational Homology Spheres ◽  
Aspherical Manifolds ◽  
Rational Homology Sphere

We show that various classes of products of manifolds do not support transitive Anosov diffeomorphisms. Exploiting the Ruelle–Sullivan cohomology class, we prove that the product of a negatively curved manifold with a rational homology sphere does not support transitive Anosov diffeomorphisms. We extend this result to products of finitely many negatively curved manifolds of dimension at least three with a rational homology sphere that has vanishing simplicial volume. As an application of this study, we obtain new examples of manifolds that do not support transitive Anosov diffeomorphisms, including certain manifolds with non-trivial higher homotopy groups and certain products of aspherical manifolds.

scholarly journals APPLICATIONS OF INVOLUTIVE HEEGAARD FLOER HOMOLOGY

2019 ◽  
pp. 1-38 ◽  
Author(s):  
Kristen Hendricks ◽  
Jennifer Hom ◽  
Tye Lidman
Keyword(s):  
Spin Structure ◽  
Floer Homology ◽  
Heegaard Floer Homology ◽  
Homology Sphere ◽  
Rational Homology ◽  
Cobordism Group ◽  
Homology Cobordism ◽  
Heegaard Floer ◽  
Correction Terms ◽  
Rational Homology Sphere

We use Heegaard Floer homology to define an invariant of homology cobordism. This invariant is isomorphic to a summand of the reduced Heegaard Floer homology of a rational homology sphere equipped with a spin structure and is analogous to Stoffregen’s connected Seiberg–Witten Floer homology. We use this invariant to study the structure of the homology cobordism group and, along the way, compute the involutive correction terms$\bar{d}$and$\text{}\underline{d}$for certain families of three-manifolds.

scholarly journals SKEIN MODULES AT THE 4TH ROOTS OF UNITY

2004 ◽  
Vol 13 (05) ◽  
pp. 571-585 ◽  
Author(s):  
ADAM S. SIKORA
Keyword(s):  
Homology Sphere ◽  
Roots Of Unity ◽  
Rational Homology ◽  
Skein Modules ◽  
Character Varieties ◽  
Kauffman Bracket ◽  
Rational Homology Sphere

The Kauffman bracket skein modules, [Formula: see text], have been calculated for A=±1 for all 3-manifolds M by relating them to the [Formula: see text]-character varieties. We extend this description to the case when A is a 4th root of 1 and M is either a surface×[0,1] or a rational homology sphere (or its submanifold).

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