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The finitistic dimension conjecture is closely connected to the symmetry of the finitistic dimension. Recent work indicates that such connection extends to one of its upper bounds, the delooping level. In this paper, we show that the same…

Representation Theory · Mathematics 2025-08-05 Ruoyu Guo

The main objective of this paper is to provide a theory for computing the Hochschild cohomology of algebras arising from a linear category with finitely many objects and zero compositions. For this purpose, we consider such a category using…

Rings and Algebras · Mathematics 2018-08-02 Cibils Claude , Lanzilotta Marcelo , Marcos N. Eduardo , Solotar Andrea

It is shown that a bounded quiver algebra having a 2-truncated oriented cycle is of infinite Hochschild homology dimension and global dimension, which generalizes a result of Solotar and Vigu\'{e}-Poirrier to nonlocal ungraded algebras…

Rings and Algebras · Mathematics 2010-04-07 Yang Han

Recently, I. Kossovskiy and R. Shafikov have settled the so-called Dimension Conjecture, which characterizes spherical hypersurfaces in ${\mathbb C}^2$ via the dimension of the algebra of infinitesimal automorphisms. In this note, we…

Complex Variables · Mathematics 2015-10-01 Alexander Isaev , Boris Kruglikov

In a general triangulated category, the finiteness of the finitistic dimension serves as a prerequisite for a categorical obstruction, via the singularity category, to the existence of bounded $t$-structures. In this paper, we investigate…

Representation Theory · Mathematics 2026-04-14 Hongxing Chen , Xiaohu Chen , Jinbi Zhang

We establish the multiplicity conjecture of Herzog, Huneke, and Srinivasan about the multiplicity of graded Cohen-Macaulay algebras over a field, for codimension two algebras and for Gorenstein algebras of codimension three. In fact, we…

Commutative Algebra · Mathematics 2007-05-23 Juan C. Migliore , Uwe Nagel , Tim Römer

Given a finite dimensional algebra $\Lambda$, we show that a frequently satisfied finiteness condition for the category ${\cal P}^{\infty}(\Lambda\rm{-mod})$ of all finitely generated (left) $\Lambda$-modules of finite projective dimension,…

Representation Theory · Mathematics 2014-07-10 B. Huisgen-Zimmermann , S. O. Smalø

Braided algebras are associative algebras endowed with a Yang-Baxter operator that satisfies certain compatibility conditions involving the multiplication. Along with Hochschild cohomology of algebras, there is also a notion of Yang-Baxter…

Quantum Algebra · Mathematics 2025-06-13 Masahico Saito , Emanuele Zappala

Let an n-algebra mean an algebra over the chain complex of the little n-cubes operad. We give a proof of Kontsevich's conjecture, which states that for a suitable notion of Hochschild cohomology in the category of n-algebras, the Hochschild…

Algebraic Topology · Mathematics 2007-05-23 P. Hu , I. Kriz , A. A. Voronov

For a Cohen-Macaulay ring $R$, we exhibit the equivalence of the bounded derived categories of certain resolving subcategories, which, amongst other results, yields an equivalence of the bounded derived category of finite length and finite…

K-Theory and Homology · Mathematics 2015-05-26 William Sanders , Sarang Sane

For a commutative local ring $R$, consider (noncommutative) $R$-algebras $\Lambda$ of the form $\Lambda = End_R(M)$ where $M$ is a reflexive $R$-module with nonzero free direct summand. Such algebras $\Lambda$ of finite global dimension can…

Commutative Algebra · Mathematics 2007-05-23 Graham J. Leuschke

There appeared not long ago a Reduction Formula for derived Hochschild cohomology, that has been useful e.g., in the study of Gorenstein maps and of rigidity w.r.t. semidualizing complexes. The formula involves the relative dualizing…

Category Theory · Mathematics 2015-11-20 Joseph Lipman

This is a report on the present state of the problem of determining the dimension of the Nichols algebra associated to a rack and a cocycle. This is relevant for the classification of finite-dimensional complex pointed Hopf algebras whose…

Quantum Algebra · Mathematics 2011-03-22 N. Andruskiewitsch , F. Fantino , G. A. Garcia , L. Vendramin

A duality theorem for the singularity category of a finite dimensional Gorenstein algebra is proved. It complements a duality on the category of perfect complexes, discovered by Happel. One of its consequences is an analogue of Serre…

Representation Theory · Mathematics 2019-05-07 Dave Benson , Srikanth B. Iyengar , Henning Krause , Julia Pevtsova

Let $\Lambda$ be a finite dimensional algebra over an algebraically closed field $k$. We survey some results on algebras of finite global dimension and address some open problems.

Representation Theory · Mathematics 2012-09-11 Dieter Happel , Dan Zacharia

In a recent manuscript, D.Vogan conjectures that four canonical globalizations of Harish-Chandra modules commute with certain n-cohomology groups. In this article we focus on the case of a complex reductive group and prove that Vogan's…

Representation Theory · Mathematics 2020-12-14 Tim Bratten , Sergio Corti

In 2005, the second author and Todorov introduced an upper bound on the finitistic dimension of an Artin algebra, now known as the {\phi}-dimension. The {\phi}-dimension conjecture states that this upper bound is always finite, a fact that…

Representation Theory · Mathematics 2022-08-25 Eric J. Hanson , Kiyoshi Igusa

We borrow ideas from Grothendieck duality theory to noncommutative algebra, and use them to prove a reduction result for Hochschild cohomology for noncommutative algebras which are finite over their center. This generalizes a result over…

Rings and Algebras · Mathematics 2015-05-19 Liran Shaul

Church-Farb-Putman formulated stability and vanishing conjectures for the high-dimensional cohomology of $\operatorname{SL}_n(\mathbb{Z})$, surface mapping class groups and automorphism groups of free groups. This is a survey on the current…

Group Theory · Mathematics 2025-10-13 Benjamin Brück

In this paper we prove that the homological dimension of an elementary amenable group over an arbitrary commutative coefficient ring is either infinite or equal to the Hirsch length of the group. Established theory gives simple group…

Group Theory · Mathematics 2019-02-26 Peter Kropholler , Conchita Martínez-Pérez