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Related papers: Fox pairings of Poincar\'{e} duality groups

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We investigate the rational cohomology of the quotient of (generalized) braid groups by the commutator subgroup of the pure braid groups. We provide a combinatorial description of it using isomorphism classes of certain families of graphs.…

Group Theory · Mathematics 2023-08-29 Filippo Callegaro , Ivan Marin

We prove a duality theorem for Cohen--Macaulay simplicial complexes. This is a generalisation of Poincar\'e Duality, framed in the language of combinatorial sheaves. Our treatment is self-contained and accessible for readers with a working…

Algebraic Topology · Mathematics 2025-02-07 Richard D. Wade , Thomas A. Wasserman

We consider the class of those Coxeter groups for which removing from the Cayley graph any tubular neighbourhood of any wall leaves exactly two connected components. We call these Coxeter groups bipolar. They include both the virtually…

Group Theory · Mathematics 2012-03-07 Pierre-Emmanuel Caprace , Piotr Przytycki

We determine the action of the product of symmetric groups on the cohomology of certain moduli of weighted pointed rational curves. The moduli spaces that we study are of stable rational curves with m+n marked points where the first m…

Algebraic Geometry · Mathematics 2017-10-31 Chitrabhanu Chaudhuri

We develop cohomological and homological theories for a profinite group $G$ with coefficients in the Pontryagin dual categories of pro-discrete and ind-profinite $G$-modules, respectively. The standard results of group (co)homology hold for…

Group Theory · Mathematics 2016-09-30 Marco Boggi , Ged Corob Cook

We define and study the Weil pairing on the moduli of twisted curves. If $X$ is a twisted curve, then we can combinatorially describe a certain subgroup and a quotient group of $\text{Pic}(X)[2]$ that are Weil dual. Moreover, the pairing…

Algebraic Geometry · Mathematics 2023-10-16 Ashwin Deopurkar

We discuss an interesting duality known to occur for certain complex reflection groups, namely the duality groups. Our main construction yields a concrete, representation theoretic realisation of this duality. This allows us to naturally…

Rings and Algebras · Mathematics 2020-07-20 Benjamin Briggs

Given a finite group $G$, we introduce "encoding pairs," which are a pair of $G$-modules $M$ and $M'$ equipped with a shifted natural isomorphism between the cohomological functors $H^\bullet(G,\mathrm{Hom}_\mathbb Z(M,-))$ and…

Group Theory · Mathematics 2024-01-02 Nir Elber

Motivated by orbifold string theory, we introduce orbifold cohomology group for any almost complex orbifold and orbifold Dolbeault cohomology for any complex orbifold. Then, we show that our new cohomology group satisfies Poincare duality…

Algebraic Geometry · Mathematics 2009-10-31 Weimin Chen , Yongbin Ruan

This paper examines a systematic method to construct a pair of (inter-related) root systems for arbitrary Coxeter groups from a class of non-standard geometric representations. This method can be employed to construct generalizations of…

Representation Theory · Mathematics 2013-03-18 Xiang Fu

Let $X$ be a connected, orientable, 5-dimensional Poincar\'{e} duality complex with torsion-free $H_1(X;\mathbb{Z})$. We show that $\Sigma X$ is homotopy equivalent to a wedge of recognisable spaces and study to what extent its homotopy…

Algebraic Topology · Mathematics 2026-01-21 Steven Amelotte , Tyrone Cutler , Tseleung So

For $G = \mathrm{GL}_2, \mathrm{SL}_2, \mathrm{PGL}_2$ we compute the intersection E-polynomials and the intersection Poincar\'e polynomials of the $G$-character variety of a compact Riemann surface $C$ and of the moduli space of $G$-Higgs…

Algebraic Geometry · Mathematics 2021-01-13 Mirko Mauri

We classify pro-$p$ Poincar\'e duality pairs in dimension two. We then use this classification to build a pro-$p$ analogue of the curve complex and establish its basic properties. We conclude with some statements concerning separability…

Group Theory · Mathematics 2018-06-21 Gareth Wilkes

In this paper, we use characteristic classes of the canonical vector bundles and the Poincar\' {e} dualality to study the structure of the real homology and cohomology groups of oriented Grassmann manifold $G(k, n)$. Show that for $k=2$ or…

Functional Analysis · Mathematics 2008-09-05 Jianwei Zhou , Jin Shi

The motivation of this paper is to construct a deformation theory of coderivations of coassociative coalgebras. We introduce a notion of a Coder pair, that is, a coassociative coalgebra with a coderivation. Then we define a proper…

Rings and Algebras · Mathematics 2023-01-31 Lei Du , Yashuang Ma , Jiangnan Xv , Yanhong Bao

We introduce tropical singular intersection homologies (non-GM and GM) with the tropical coefficients on rational polyhedral spaces using their filtrations. We investigate their fundamental properties. In the non-GM case, we give a…

Algebraic Geometry · Mathematics 2026-03-30 Junta Kamiya

Intersection homology with coefficients in a field restores Poincar\'e duality for some spaces with singularities, as pseudomanifolds. But, with coefficients in a ring, the behaviours of manifolds and pseudomanifolds are different. This…

Algebraic Topology · Mathematics 2020-09-22 Martintxo Saralegi-Aranguren , Daniel Tanré

This paper provides an introduction to equivariant cohomology and homology using the approach of Goresky, Kottwitz, and MacPherson. When a group G acts suitably on a variety X, the equivariant cohomology of X can be computed using the…

Algebraic Geometry · Mathematics 2007-05-23 Julianna S. Tymoczko

This paper studies unitary representations with Dirac cohomology for complex groups, in particular relations to unipotent representations

Representation Theory · Mathematics 2010-07-09 Dan Barbasch , Pavle Pandžić

We introduce a notion of a Fox pairing in a group algebra and use Fox pairings to define automorphisms of the Malcev completions of groups. These automorphisms generalize to the algebraic setting the action of the Dehn twists in the group…

Geometric Topology · Mathematics 2014-07-17 Gwenael Massuyeau , Vladimir Turaev