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When identified with sequences of irreducible Hermitian-Einstein connections, sequences of stable holomorphic bundles of fixed topological type and bounded degree on a compact complex surface equipped with a Gauduchon metric are shown to…

alg-geom · Mathematics 2008-02-03 Nicholas P. Buchdahl

We compute the dimensions of the Hochschild cohomology of symmetric groups over prime fields in low degrees. This involves us in studying some partition identities and generating functions of the dimensions in any fixed degree of the…

Group Theory · Mathematics 2022-04-22 David Benson , Radha Kessar , Markus Linckelmann

We introduce a formalism to produce several families of spectral sequences involving the derived functors of the limit and colimit functors over a finite partially ordered set. The first type of spectral sequences involves the left derived…

Commutative Algebra · Mathematics 2022-10-18 Josep Àlvarez Montaner , Alberto F. Boix , Santiago Zarzuela

A conjecture due to Y. Han asks whether that Hochschild homology groups of a finite dimensional algebra vanish for sufficiently large degrees would imply that the algebra is of finite global dimension. We investigate this conjecture from…

Representation Theory · Mathematics 2024-09-04 Ren Wang , Xiaoxiao Xu , Jinbi Zhang , Guodong Zhou

We show that the Rouquier dimension of the category of perfect complexes over a regular ring is precisely the Krull dimension of the ring. Previously, it was known that the Krull dimension is an upper bound, the lower bound however was not…

Commutative Algebra · Mathematics 2025-07-01 Janina C. Letz

Let $S$ be a standard graded polynomial ring over a field, and $I$ be a homogeneous ideal that contains a regular sequence of degrees $d_1,\ldots,d_n$. We prove the Eisenbud-Green-Harris conjecture when the forms of the regular sequence…

Commutative Algebra · Mathematics 2020-11-20 Giulio Caviglia , Alessandro De Stefani

The geometric and algebraic theory of monomial ideals and multigraded modules is initiated over real-exponent polynomial rings and, more generally, monoid algebras for real polyhedral cones. The main results include the generalization of…

Commutative Algebra · Mathematics 2025-11-11 Ezra Miller

In this paper, we present a generalisation of a theorem of David and Rob Pollack. In 'A construction of rigid analytic cohomology classes for congruence subgroups of SL(3,Z)', they give a very general argument for lifting ordinary…

Number Theory · Mathematics 2018-06-18 Chris Williams

This paper analyzes the second cohomology group of a linear cycle set with coefficients in an abelian group I, for linear cycle sets with commutative adjoint operation, focusing on the finite abelian case. It aims to classify extensions of…

Group Theory · Mathematics 2025-10-14 Jorge Guccione , Juan José Guccione , Christian Valqui

The quandle homology theory is generalized to the case when the coefficient groups admit the structure of Alexander quandles, by including an action of the infinite cyclic group in the boundary operator. Theories of Alexander extensions of…

Geometric Topology · Mathematics 2014-10-01 J. Scott Carter , Mohamed Elhamdadi , Masahico Saito

In this article we extend a previous definition of Castelnuovo-Mumford regularity for modules over an algebra graded by a finitely generated abelian group. Our notion of regularity is based on Maclagan and Smith's definition, and is…

Commutative Algebra · Mathematics 2012-04-06 Nicolás Botbol , Marc Chardin

We review the depth two and Hopf algebroid-Galois theory in math.RA/0108067 and specialize to induced representations of semisimple algebras and character theory of finite groups. We show that depth two subgroups over the complex numbers…

Group Theory · Mathematics 2007-05-23 Lars Kadison , Burkhard Külshammer

We prove a general homological stability theorem for certain families of groups equipped with product maps, followed by two theorems of a new kind that give information about the last two homology groups outside the stable range. (These…

Algebraic Topology · Mathematics 2020-07-13 Richard Hepworth

In [F. Xu, On the cohomology rings of small categories, J. Pure Appl. Algebra 212 (2008), 2555-2569], Xu constructs a LHS-spectral sequence for target regular extensions of small categories. We extend this construction to ext-groups and…

Algebraic Topology · Mathematics 2024-02-01 Ergun Yalcin

In a finite real reflection group, the reflection length of each element is equal to the codimension of its fixed space, and the two coincident functions determine a partial order structure called the absolute order. In complex reflection…

Combinatorics · Mathematics 2025-05-20 Joel Brewster Lewis , Jiayuan Wang

We present an algebraic framework for the computation of low-degree cohomology of a class of bigraded complexes which arise in Poisson geometry around (pre)symplectic leaves. We also show that this framework can be applied to the more…

Symplectic Geometry · Mathematics 2019-03-06 Andrés Pedroza , Eduardo Velasco-Barreras , Yury Vorobiev

In this m\'emoire we study quasiperiodic cocycles in semi-simple compact Lie groups. For the greatest part of our study, we will focus ourselves to one-frequency cocyles. We will prove that $C^{\infty}$ reducible cocycles are dense in the…

Dynamical Systems · Mathematics 2018-09-21 Nikolaos Karaliolios

Different and distinct notions of regularity for modules exist in the literature. When these notions are restricted to commutative rings, they all coincide with the well-known von-Neumann regularity for rings. We give new characterizations…

Commutative Algebra · Mathematics 2023-01-10 Philly Ivan Kimuli , David Ssevviiri

We consider continuous extensions of minimal rotations on a locally connected compact group X by arbitrary locally compact Lie groups and prove regularity (i.e. the existence of orbit closures which project onto the whole basis X) in…

Dynamical Systems · Mathematics 2008-04-17 Ulrich Haboeck , Vyacheslav Kulagin

Over the complex numbers, the complement of a collection of hyperplanes is a widely-studied object; the cohomology ring, in particular, is known to have a structure depending only on the combinatorial properties of the intersection of…

Algebraic Topology · Mathematics 2015-08-25 William Schlieper