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Related papers: Bounded characteristic classes and flat bundles

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We show that each integral Borel cohomology class of a connected Lie group G can be represented by a Borel bounded cocycle if and only if the radical of G is linear. This leads to a generalization of Gromov's boundedness theorem on…

Algebraic Topology · Mathematics 2009-05-14 Indira Chatterji , Guido Mislin , Christophe Pittet , Laurent Saloff-Coste

For a compact Lie group G we show that if the representing spectrum for Borel cohomology generates its category of modules if G is connected. For a closed subgroup H of G we consider the map C^*(BG)--->C^*(BH) and establish the sense in…

Algebraic Topology · Mathematics 2018-08-23 J. P. C. Greenlees

Let $G$ be a minimal locally compact groupoid with compact metrizable unit space and let $E$ be a continuous $G$-Hilbert bundle. We show that a bounded continuous cocycle $c: G\ra r^*E$ is necessarily a continuous coboundary. This is a…

Operator Algebras · Mathematics 2011-09-21 Jean Renault

The characteristic forms in the bundle of connections of a principal bundle P over M determine the characteristic classes of P for degree less or equal to the dimension of M, and differential forms on the space of connections for higher…

Mathematical Physics · Physics 2015-06-26 Roberto Ferreiro Perez

We establish the homological foundations for studying polynomially bounded group cohomology, and show that the natural map from PH^*(G;Q) to H^*(G;Q) is an isomorphism for a certain class of groups.

K-Theory and Homology · Mathematics 2011-10-04 Crichton Ogle

Characteristic classes of oriented vector bundles can be identified with cohomology classes of the disjoint union of classifying spaces BSO_n of special orthogonal groups SO_n with n=0,1,... A characteristic class is stable if it extends to…

Geometric Topology · Mathematics 2009-10-27 Rustam Sadykov

Let G be a connected complex Lie group. We show that any flat principal G-bundle over any finite CW-complex pulls back to a trivial bundle over some finite covering space of the base space if and only if each real characteristic class of…

Algebraic Topology · Mathematics 2013-08-08 Indira Chatterji , Guido Mislin , Christophe Pittet

In the first part of this paper, we propose a uniform interpretation of characteristic classes as obstructions to the reduction of the structure group and to the existence of an equivariant extension of a certain homomorphism defined a…

Algebraic Topology · Mathematics 2018-10-16 Martina Rovelli

There are characteristic classes that are the obstructions to the vanishing of the differentials in the Lyndon-Hochischild-Serre spectral sequence of an extension of an integral lattice L by a group G. These characteristic classes exist in…

Algebraic Topology · Mathematics 2009-06-18 Nansen Petrosyan

We prove that if the prime graphs in a graph class have bounded lettericity, then the entire class has bounded lettericity if and only if it does not contain arbitrary large matchings, co-matchings, or a family of graphs that we call…

Combinatorics · Mathematics 2021-11-17 Robert Ferguson , Vincent Vatter

Let $d \in \N$ and let $\D^d$ denote the class of all pairs $(R,M)$ in which $R = \bigoplus_{n \in \N_0} R_n$ is a Noetherian homogeneous ring with Artinian base ring $R_0$ and such that $M$ is a finitely generated graded $R$-module of…

Commutative Algebra · Mathematics 2009-05-18 Markus Brodmann , Maryam Jahangiri , Cao Huy Linh

A discrete group with word-length (G,L) is B-isocohomological for a bounding classes B if the comparison map from B-bounded cohomology to ordinary cohomology (with complex coefficients) is an isomorphism; it is strongly B-isocohomological…

K-Theory and Homology · Mathematics 2013-07-10 R. Ji , C. Ogle , B. Ramsey

Let $M$ be a complete hyperbolic $n$-manifold, $n\geq 2$. Via integration over geodesic simplices, any closed bounded differential 2-form on $M$ defines a bounded cohomology class in $H^2_b(M)$. It was proved by Barge and Ghys (for $n=2$)…

Geometric Topology · Mathematics 2026-04-20 Gian Maria Dall'Ara , Roberto Frigerio , Ervin Hadziosmanovic

In this paper we study the variability and rigidity of secondary characteristic classes which arise from flat connections on a manifold. Considering the connection as a Lie-algebra valued one-form, we study the characteristic map from Lie…

Differential Geometry · Mathematics 2007-05-23 Jerry Lodder

We prove that the groups of orientation-preserving homeomorphisms and diffeomorphisms of $\mathbb{R}^n$ are boundedly acyclic, in all regularities. This is the first full computation of the bounded cohomology of a transformation group that…

Geometric Topology · Mathematics 2024-09-27 Francesco Fournier-Facio , Nicolas Monod , Sam Nariman , Alexander Kupers

In this paper, we characterize the second bounded characteristic classes of foliated bundles in terms of the non-descendible quasi-morphisms on the universal covering of the structure group. As its application, we study the boundedness of…

Symplectic Geometry · Mathematics 2022-03-16 Morimichi Kawasaki , Shuhei Maruyama

We provide a description of certain invariance properties of completely bounded bimodule maps in terms of their symbols. If $\mathbb{G}$ is a locally compact quantum group, we characterise the completely bounded…

Operator Algebras · Mathematics 2019-01-29 M. Alaghmandan , I. G. Todorov , L. Turowska

Let G be a group which is topologically a CW-complex, BG a classifying space for G, and A a discrete abelian group. To a central extension of G by A, one can associate a cohomology class in $H^2(BG,A)$. We show this association is…

Algebraic Topology · Mathematics 2024-03-05 Rohit Joshi , Steven Spallone

We prove that group homology of the diffeomorphism group of $\#^g S^n \times S^n$ as a discrete group is independent of $g$ in a range, provided that $n>2$. This answers the high dimensional version of a question posed by Morita about…

Algebraic Topology · Mathematics 2017-09-12 Sam Nariman

We examine the topological characteristic cohomology classes of complexified vector bundles. In particular, all the classes coming from the real vector bundles underlying the complexification are determined.

K-Theory and Homology · Mathematics 2013-12-24 Alexander D. Rahm
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