English
Related papers

Related papers: Cohomology and removable subsets

200 papers

We study high dimensional expansion beyond simplicial complexes (posets) and focus on $q$-complexes which are complexes whose basic building blocks are linear spaces. We show that the complete $q$-complex (consists of all subspaces of a…

Combinatorics · Mathematics 2024-01-24 Ran Tessler , Elad Tzalik

We introduce the notion of spaces with weak relative cohomology and show the acyclicity of the complement $Q\setminus X$ in the Hilbert cube $Q$ of a compactum $X$ with weak relative cohomology. As a corollary we obtain the acyclicity of…

General Topology · Mathematics 2016-03-23 Ashwini Amarasinghe , Alexander Dranishnikov

Electromagnetic modeling provides an interesting context to present a link between physical phenomena and homology and cohomology theories. Over the past twenty-five years, a considerable effort has been invested by the computational…

Algebraic Topology · Mathematics 2011-11-11 Paweł Dłotko , Ruben Specogna

We establish a Galois-theoretic interpretation of cohomology in semi-abelian categories: cohomology with trivial coefficients classifies central extensions, also in arbitrarily high degrees. This allows us to obtain a duality, in a certain…

Category Theory · Mathematics 2015-11-24 Diana Rodelo , Tim Van der Linden

We generalize some known results on the relation between the cohomological and projective dimension. Then we examine the set-theoretically Cohen-Macaulay ideals to find some cohomological characterization of these kind of ideals.

Commutative Algebra · Mathematics 2021-06-15 Majid Eghbali , Alberto F. Boix

Ends and end cohomology are powerful invariants for the study of noncompact spaces. We present a self-contained exposition of the topological theory of ends and prove novel extensions including the existence of an exhaustion of a proper…

Algebraic Topology · Mathematics 2025-04-17 William G. Bass , Jack S. Calcut

We prove that for any field k of characteristic p>0, any separated scheme X of finite type over k, and any overconvergent F-isocrystal E over X, the rigid cohomology H^i(X, E) and rigid cohomology with compact supports H^i_c(X,E) are finite…

Algebraic Geometry · Mathematics 2007-05-23 Kiran S. Kedlaya

This paper expands on and refines some known and less well-known results about the finite subset spaces of a simplicial complex $X$ including their connectivity and their top homology groups. It also discusses the inclusion of the…

Algebraic Topology · Mathematics 2009-08-03 Sadok Kallel , Denis Sjerve

We begin with an improvement to an extension result for subharmonic functions of Blanchet et al. With the aid of this improvement we then give extension results for subharmonic functions, for separately subharmonic functions, for harmonic…

Analysis of PDEs · Mathematics 2019-07-22 Juhani Riihentaus

In this paper we develop a new homology theory of associative algebras called semiinfinite cohomology in a derived category setting. We show that in the case of small quantum groups the zeroth semiinfinite cohomology of the trivial module…

q-alg · Mathematics 2009-10-30 Sergey Arkhipov

Geometric conditions are given so that the leafwise reduced cohomology is of infinite dimension, specially for foliations with dense leaves on closed manifolds. The main new definition involved is the intersection number of subfoliations…

Geometric Topology · Mathematics 2013-11-15 Jesús A. Álvarez López , Gilbert Hector

The notion of a duality between two derived functors as well as an extension theorem for derived functors to larger categories in which they need not be defined is introduced. These ideas are then applied to extend and study the coext…

Rings and Algebras · Mathematics 2014-02-19 Anastasis Kratsios

Let K be an algebraically closed field of characteristic zero, endowed with a complete nonarchimedean norm. Let X be a K-rigid analytic variety and \Sigma a semianalytic subset of X. Then the closure of \Sigma in X with respect to the…

Differential Geometry · Mathematics 2016-09-07 Hans Schoutens

Locally compact separable metrizable spaces are characterized among all metrizable spaces as those that admit a cofinal sequence $K_1\subset K_2\subset\cdots$ of compact subsets. Their \v{C}ech cohomology is well-understood due to Petkova's…

Geometric Topology · Mathematics 2022-11-21 Sergey A. Melikhov

We generalize a recent result by J.F. Carlson to finite tensor categories having finitely generated cohomology. Specifically, we show that if the Krull dimension of the cohomology ring is sufficiently large, then there exist infinitely many…

K-Theory and Homology · Mathematics 2023-01-19 Petter Andreas Bergh

We show that finite-dimensional Lie algebras over a field of characteristic zero such that their high-degree cohomology in any finite-dimensional non-trivial irreducible module vanishes, are, essentially, direct sums of semisimple and…

Rings and Algebras · Mathematics 2009-06-06 Pasha Zusmanovich

In this short note, we observe that Theorem 3.1 in arXiv:1508.00682 for semiorthogonal indecomposability of the derived category of smooth DM stacks based on the canonical bundle can be extended to the case of projective varieties with…

Algebraic Geometry · Mathematics 2021-04-30 Dylan Spence

In this article, we first prove a general result in topology which states that every quasi-component of a quasi-spectral space is connected. \\ As an application, the structure of the connected components of every quasi-compact…

Commutative Algebra · Mathematics 2026-04-17 Abolfazl Tarizadeh

Supersymmetric states in M-theory are mapped after compactification to perturbatively non-supersymmetric states in type IIA string theory, with the supersymmetric parts being encoded in the non-perturbative section of the string theory. An…

High Energy Physics - Theory · Physics 2024-03-06 Andrei T. Patrascu

We highlight an intrinsic connection between classical quadrature domains and the well-studied theme of removable singularities of analytic sets in several complex variables. Exploiting this connection provides a new framework to recover…

Complex Variables · Mathematics 2016-12-21 Kaushal Verma