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In the present paper we develop a small cancellation theory for associative algebras with a basis of invertible elements. Namely, we study quotients of a group algebra of a free group and introduce three axioms for the corresponding…

Rings and Algebras · Mathematics 2024-01-17 A. Atkarskaya , A. Kanel-Belov , E. Plotkin , E. Rips

The theory of small cancellation groups is well known. In this paper we introduce the notion of Group-like Small Cancellation Ring. This is the main result of the paper. We define this ring axiomatically, by generators and defining…

Rings and Algebras · Mathematics 2022-06-16 A. Atkarskaya , A. Kanel-Belov , E. Plotkin , E. Rips

We prove that cancellation of reflexive modules over affine rings holds under some restrictions. We construct examples to show that this is false even over polynomial rings without the extra assumptions.

Commutative Algebra · Mathematics 2007-05-23 N. Mohan Kumar

We introduce and study a relative cancellation property for associative algebras. We also prove a characterization result for polynomial rings which partially answers a question of Kraft.

Representation Theory · Mathematics 2025-11-11 Hongdi Huang , Zahra Nazemian , Yanhua Wang , James J. Zhang

The purpose of this paper is to prove that certain limits of polynomial rings are themselves polynomial rings, and show how this observation can be used to deduce some interesting results in commutative algebra. In particular, we give two…

Commutative Algebra · Mathematics 2022-08-16 Daniel Erman , Steven V Sam , Andrew Snowden

It is shown that the reduced C*-algebra of a nontrivial linear group $\Gamma<GL_{d}(k)$ with trivial amenable radical is selfless. Thus selflessness and simplicity coincide for reduced C*-algebras of linear groups. Similar results are…

Operator Algebras · Mathematics 2026-02-16 Itamar Vigdorovich

We extend fundamental results of small cancellation theory to groups whose presentations satisfy the generalizations of the classical C(6) and C(7) conditions in graphical small cancellation theory. Using these graphical small cancellation…

Group Theory · Mathematics 2014-07-25 Dominik Gruber

Using small cancellation for rotating families of groups, we construct new examples of aspherical polyhedra.

Group Theory · Mathematics 2013-02-28 Rémi Coulon

We use a simple geometric argument and small cancellation properties of link groups to prove that alternating links are non-trivial. This proof uses only classic results in topology and combinatorial group theory.

Geometric Topology · Mathematics 2012-03-01 Iain Moffatt

We call a simplicial complex algebraically rigid if its Stanley-Reisner ring admits no nontrivial infinitesimal deformations, and call it inseparable if does not allow any deformation to other simplicial complexes. Algebraically rigid…

Commutative Algebra · Mathematics 2021-04-07 Klaus Altmann , Mina Bigdeli , Juergen Herzog , Dancheng Lu

We construct small cancellation labellings for some infinite sequences of finite graphs of bounded degree. We use them to define infinite graphical small cancellation presentations of groups. This technique allows us to provide examples of…

Group Theory · Mathematics 2020-05-19 Damian Osajda

We give two equivalent definitions of sigma algebras that are atomless conditionally to a smaller sigma algebra.

Probability · Mathematics 2020-03-23 Freddy Delbaen

Let $\mf{g}$ be any finite-dimensional Lie algebra with Killling form $B$. Let $\mf{h}$ be a subalgebra of $\mf{g}$ on which the Killing form is non degenerate. Then $\mf{h}$ is reductive.

Rings and Algebras · Mathematics 2007-12-03 Stuart Armstrong

We exhibit a non-constructive proof in which anti-automorphisms are not valuation-preserving and hence non-isometric

Rings and Algebras · Mathematics 2016-03-29 Abdullah Naeem Malik , Tayyab Kamran

This paper introduces and studies nil-reversible rings wherein we call a ring R nil-reversible if the left and right annihilators of every nilpotent element of R are equal. Reversible rings (and hence reduced rings) form a proper subclass…

Rings and Algebras · Mathematics 2021-02-24 Sanjiv Subba , Tikaram Subedi

Let $R$ be an algebra over a commutative ring $k$. Suppose that $R$ is endowed with a descending filtration indexed on an ordered group $(G,<)$ such that the restriction to $k$ is positive. We show that the existence of free algebras on a…

Rings and Algebras · Mathematics 2018-06-29 Javier Sánchez

It has recently been shown that a minimal reversible nonsymmetric ring has order 256 answering a questioned original posed in a paper on a taxonomy of 2-primal rings. Answers to similar questions on minimal rings relating to this taxonomy…

Rings and Algebras · Mathematics 2020-01-03 Henry Chimal-Dzul , Steve Szabo

We prolonge the list of C*-algebras for which all extensions by any stable separable C*-algebra are semi-invertible. In particular, we handle certain amalgamations, both of C*-algebras and of groups. Concerning groups we consider both…

Operator Algebras · Mathematics 2010-05-13 Vladimir Manuilov , Klaus Thomsen

We develop a general ring theory in the o-minimal setting culminating in a description of all the definable rings in an arbitrary o-minimal structure. We show that every definably connected ring with non-trivial multiplication defines an…

Logic · Mathematics 2025-03-05 Annalisa Conversano

We give a simplified approach to the cubulation of small-cancellation quotients of free products of cubulated groups. We construct fundamental groups of compact nonpositively curved cube complexes that do not virtually split.

Group Theory · Mathematics 2022-05-10 Kasia Jankiewicz , Daniel T. Wise
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