English
Related papers

Related papers: Leray theorems in bounded cohomology theory

200 papers

Gromov and Ivanov established an analogue of Leray's theorem on cohomology of contractible covers for bounded cohomology of amenable covers. We present an alternative proof of this fact, using classifying spaces of families of subgroups.

Algebraic Topology · Mathematics 2020-06-09 Clara Loeh , Roman Sauer

We establish a relative version of Gromov's Vanishing Theorem in the presence of amenable open covers with small multiplicity, extending a result of Li, L\"oh, and Moraschini. Our approach relies on Gromov's theory of multicomplexes.

Algebraic Topology · Mathematics 2025-11-20 Pietro Capovilla

The paper is devoted to an adaptation of author's approach to Leray theorems in bounded cohomology theory to infinite chains. The main results are a stronger and more general form of Gromov's Vanishing-finiteness theorem and a…

Algebraic Topology · Mathematics 2020-12-17 Nikolai V. Ivanov

In the context of complex algebraic varieties, the decomposition theorem for semi-small maps provides a decomposition of the direct image of the constant sheaf. In this work, we develop a decomposition theorem for branched coverings of…

Algebraic Topology · Mathematics 2026-03-02 Shahryar Ghaed Sharaf

We develop an explicit covering theory for complexes of groups, parallel to that developed for graphs of groups by Bass. Given a covering of developable complexes of groups, we construct the induced monomorphism of fundamental groups and…

Group Theory · Mathematics 2007-10-04 Seonhee Lim , Anne Thomas

A classic result states that on any locally contractible and paracompact topological space, singular cohomology and sheaf cohomology are isomorphic. A result by Ramanan claims that the paracompactness assumption may be removed, but…

Algebraic Topology · Mathematics 2016-03-25 Yehonatan Sella

We study the cohomology theory of sheaf complexes for open embeddings of topological spaces and related subjects. The theory is situated in the intersection of the general Cech theory and the theory of derived categories. That is to say, on…

Algebraic Topology · Mathematics 2018-10-16 Tatsuo Suwa

The paper is devoted to a generalized and improved version of author's approach to Gromov bounded cohomology theory. In particular, the awkward countability assumption is removed and the aspects related to homological algebra are clarified.…

Algebraic Topology · Mathematics 2020-12-17 Nikolai V. Ivanov

We introduce a bounded version of Bredon cohomology for groups relative to a family of subgroups. Our theory generalizes bounded cohomology and differs from Mineyev--Yaman's relative bounded cohomology for pairs. We obtain cohomological…

Group Theory · Mathematics 2023-05-17 Kevin Li

For a smooth finite cyclic covering over a projective space of dimension greater than one, we show that the group of automorphisms acts faithfully on the cohomology except for a few cases. In characteristic zero, we study the equivariant…

Algebraic Geometry · Mathematics 2021-12-02 Renjie Lyu , Xuanyu Pan

We study twisted cohomologies with paracompactifying families of supports. The Kunneth theorems, Leray-Hirsch theorems and self-intersection formulae are established. Based on these results, we eventually give explicit expressions of…

Algebraic Geometry · Mathematics 2020-10-08 Lingxu Meng

In this dissertation, we investigate the cohomology theory of restricted Lie algebras. The representation theory of restricted Lie algebras is reviewed including a description of the restricted universal enveloping algebra. In the case of…

Representation Theory · Mathematics 2007-05-23 Tyler J. Evans

We describe the standard and Leray filtrations on the cohomology groups with compact supports of a quasi projective variety with coefficients in a constructible complex using flags of hyperplane sections on a partial compactification of a…

Algebraic Geometry · Mathematics 2009-01-07 Mark Andrea A. de Cataldo

Generalising a previous work of Jiang and Sheng, a cohomology theory for differential Lie algebras of arbitrary weight is introduced. The underlying $L_\infty[1]$-structure on the cochain complex is also determined via a generalised version…

Rings and Algebras · Mathematics 2024-03-28 Weiguo Lyu , Zihao Qi , Jian Yang , Guodong Zhou

In this thesis, we introduce a new cohomology theory associated to a Lie 2-algebras and a new cohomology theory associated to a Lie 2-group. These cohomology theories are shown to extend the classical cohomology theories of Lie algebras and…

Differential Geometry · Mathematics 2018-11-09 Camilo Angulo

We prove a theorem of Leray-Hirsch type and give an explicit blow-up formula for Dolbeault cohomology on (\emph{not necessarily compact}) complex manifolds. We give applications to strongly $q$-complete manifolds and the…

Algebraic Geometry · Mathematics 2021-08-18 Lingxu Meng

The comparison map from bounded cohomology to singular cohomology plays an important role in the study of bounded cohomology theory and its applications. The vanishing and covering theorems of Gromov and Ivanov show interesting and useful…

Algebraic Topology · Mathematics 2022-10-25 George Raptis

In this note we show that a particular homological nerve theorem, which was originally proved for a finite cover of a simplicial complex by subcomplexes, also holds for an open cover of an arbitrary topological space. The motivation for…

Algebraic Topology · Mathematics 2022-10-04 Patrick Gillespie

In this short note, we will explain that the good moduli space morphisms behave as if they are proper when we consider sheaf operations, though they are not separated. For example, the decomposition theorem and the base change theorem hold…

Algebraic Geometry · Mathematics 2024-08-13 Tasuki Kinjo

A number of techniques in Lorentzian geometry, such as those used in the proofs of singularity theorems, depend on certain smooth coverings retaining interesting global geometric properties, including causal ones. In this note we give…

Differential Geometry · Mathematics 2021-02-16 Ettore Minguzzi , Ivan P. Costa e Silva
‹ Prev 1 2 3 10 Next ›