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Related papers: Amalgams of nilpotent groups of class two

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We show that elementary abelian direct factors can be disregarded in the study of the modular isomorphism problem. Moreover, we obtain four new series of abelian invariants of the group base in the modular group algebra of a finite…

Rings and Algebras · Mathematics 2023-09-25 Leo Margolis , Taro Sakurai , Mima Stanojkovski

The number of subgroups and the number of cyclic subgroups are natural combinatorial invariants of a finite group. We investigate how restrictions on these quantities, together with the number of distinct prime divisors of $|G|$, enforce…

Group Theory · Mathematics 2026-04-10 Angsuman Das , Hiranya Kishore Dey , Khyati Sharma

For every $n\in \mathbb{N}$ we obtain a separable II$_1$ factor $M$ and a maximally abelian subalgebra $A\subset M$ such that the space of maximally amenable extensions of $A$ in $M$ is affinely identified with the $n$ dimensional…

Operator Algebras · Mathematics 2024-10-16 Srivatsav Kunnawalkam Elayavalli , Gregory Patchell

We investigate border ranks of twisted powers of polynomials and smoothability of symmetric powers of algebras. We prove that the latter are smoothable. For the former, we obtain upper bounds for the border rank in general and prove that…

Algebraic Geometry · Mathematics 2025-09-01 Cosimo Flavi , Joachim Jelisiejew , Mateusz Michałek

We use continuous model theory to obtain several results concerning isomorphisms and embeddings between II_1 factors and their ultrapowers. Among other things, we show that for any II_1 factor M, there are continuum many nonisomorphic…

Operator Algebras · Mathematics 2017-05-17 Ilijas Farah , Bradd Hart , David Sherman

In this paper, we systematically investigate the nilpotentizer and nilpotent graph for a Lie superalgebra over the field of characteristic not equal to 2. First, we establish some fundamental properties of the nilpotentizer. Next, we show…

Rings and Algebras · Mathematics 2026-02-11 Baojin Zhang , Liming Tang

We construct a `weak' version EM^w(K) of Lack & Street's 2-category of monads in a 2-category K, by replacing their compatibility constraint of 1-cells with the units of monads by an additional condition on the 2-cells. A relation between…

Category Theory · Mathematics 2012-01-27 Gabriella Böhm

A (vector space) basis B of a Lie algebra is said to be very nilpotent if all the iterated brackets of elements of B are nilpotent. In this note, we prove a refinement of Engel's Theorem. We show that a Lie algebra has a very nilpotent…

Representation Theory · Mathematics 2010-11-24 Bulois Michael

We exhibit an extension of the category of class two nilpotent groups. It has the same objects but, unlike the latter, its morphisms are closed under pointwise addition of maps. At the same time the class of its morphisms is much smaller…

Group Theory · Mathematics 2007-05-23 Mamuka Jibladze , Teimuraz Pirashvili

This paper describes how to use subgroups to parameterize unipotent classes in the classical algebraic group in characteristic 2. These results can be viewed as an extension of the Bala-Carter Theorem, and give a convenient way to compare…

Group Theory · Mathematics 2008-05-08 W. Ethan Duckworth

Let $X$ be a smooth complex quasi-projective variety that is special in the sense of Campana. We prove that the monodromy group of any complex local system on $X$ is virtually nilpotent of class at most $2$. This result sharply refines a…

Algebraic Geometry · Mathematics 2026-04-08 Junyan Cao , Ya Deng , Christopher D. Hacon , Mihai Paun

We describe the nilpotent subgroups of the group Bir(P^2(C)) of birational transformations of the complex projective plane. Let N be a nilpotent subgroup of class k>1; then either each element of N has finite order, or N is virtually…

Group Theory · Mathematics 2007-05-23 Julie Deserti

In the present paper we describe absolute nilpotent and some idempotent elements of an n- dimensional evolution algebra corresponding to two permutations and we decompose such algebras to the direct sum of evolution algebras corresponding…

Rings and Algebras · Mathematics 2020-05-13 B. A. Narkuziyev

We consider the problem of classifying (possibly noncommutative) R-algebras of low rank over an arbitrary base ring R. We first classify algebras by their degree, and we relate the class of algebras of degree 2 to algebras with a standard…

Number Theory · Mathematics 2010-09-08 John Voight

In this article, we investigate the representability of actions of the category $\mathsf{Nil}_2(\mathsf{Grp})$ of $2$-nilpotent groups. We first provide an algebraic characterisation of derived actions in $\mathsf{Nil}_2(\mathsf{Grp})$ by…

Category Theory · Mathematics 2026-04-27 Alessandro Dioguardi Burgio , Manuel Mancini , Tim Van der Linden

In this paper we study subalgebras of complex finite dimensional evolution algebras. We obtain the classification of nilpotent evolution algebras whose any subalgebra is an evolution subalgebra with a basis which can be extended to a…

Rings and Algebras · Mathematics 2014-12-08 L. M. Camacho , A. Kh. Khudoyberdiyev , B. A. Omirov

The homological theory of Auslander-Platzeck-Todorov on idempotent ideals laid much of the groundwork for higher Auslander-Reiten theory, providing the key technical lemmas for both higher Auslander correspondence as well as the…

Representation Theory · Mathematics 2021-02-04 Jordan McMahon

We construct approximately inner actions of discrete amenable groups on strongly amenable subfactors of type II_1 with given invariants, and obtain classification results under some conditions. We also study the lifting of the relative \chi…

Operator Algebras · Mathematics 2007-05-23 Toshihiko Masuda

The distributive property can be studied through bilinear maps and various morphisms between these maps. The adjoint-morphisms between bilinear maps establish a complete abelian category with projectives and admits a duality. Thus the…

Category Theory · Mathematics 2012-05-04 James B. Wilson

In this paper, several theorems of Macdonald \cite{Mac1961,Mac1962} on the varieties of nilpotent groups will be generalized to the case of Lie rings. We consider three varieties of Lie rings of any characteristic associated with some…

Mathematical Physics · Physics 2020-03-02 Yin Chen , Runxuan Zhang