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We provide sufficient conditions for a free amalgamated product of torsionfree nilpotent groups to be residually nilpotent. We also characterise the residual nilpotence of certain higher-dimensional amalgams of unipotent groups over the…

Group Theory · Mathematics 2026-04-13 Pierre-Emmanuel Caprace , Timothée Marquis

We determine the structure of a finite subset $A$ of an abelian group given that $|2A|<3(1-\epsilon)|A|$, $\epsilon>0$; namely, we show that $A$ is contained either in a "small" one-dimensional coset progression, or in a union of fewer than…

Number Theory · Mathematics 2020-10-27 Vsevolod F. Lev

In this short note, we improve on a recent result by the authors. We show that infinite volume torsion free discrete subgroups of higher rank Lie groups have homological dimension gap at least one-eighth of the real rank, provided the…

Geometric Topology · Mathematics 2025-04-29 Chris Connell , D. B. McReynolds , Shi Wang

A famous result of Freiman describes the structure of finite sets A of integers with small doubling property. If |A + A| <= K|A| then A is contained within a multidimensional arithmetic progression of dimension d(K) and size f(K)|A|. Here…

Number Theory · Mathematics 2007-05-23 Ben Green , Imre Z. Ruzsa

In this paper, we study lower bounds on the K-theory of the maximal $C^*$-algebra of a discrete group based on the amount of torsion it contains. We call this the finite part of the operator K-theory and give a lower bound that is valid for…

Operator Algebras · Mathematics 2013-08-23 Shmuel Weinberger , Guoliang Yu

Let $G$ be a group and let $A\subseteq G$ be non-empty. We call $A$ an asymptotic $(r,l)$-approximate group if, for a fixed dilation factor $r$, the larger product sets $A^{hr}$ can, for all sufficiently large $h$, be covered by a bounded…

Group Theory · Mathematics 2026-05-12 Arindam Biswas

We study a certain class of non-maximal rank contractions of the nilpotent Lie algebra $\frak{g}_{m}$ and show that these contractions are completable Lie algebras. As a consequence a family of solvable complete Lie algebras of non-maximal…

Rings and Algebras · Mathematics 2007-05-23 Rutwig Campoamor-Stursberg

In the paper we study irreducible representations of some nilpotent groups of finite abelian total rank. The main result of the paper states that if a torsion-free minimax group $G$ of nilpotency class 2 admits a faithful irreducible…

Representation Theory · Mathematics 2024-12-30 Anatolii V. Tushev

We study finite-dimensional nonassociative algebras. We prove the implicit function theorem for such algebras. This allows us to establish a correspondence between such algebras and quasigroups, in the spirit of classical correspondence…

Rings and Algebras · Mathematics 2022-08-23 Yuri Bahturin , Alexander Olshanskii

Gromov claimed, with a sketch of proof, that simply connected nilpotent Lie groups have polynomially bounded filling invariants. The literature establishes this, often with a stronger conclusion where the exponent of polynomiality is…

Group Theory · Mathematics 2026-03-30 Gabriel Pallier

We derive double coset formulae for the genus and extended genus of a finitely generated nilpotent group G, using the notions of bounded and bounded above automorphisms of $\prod G_S$, which are defined relative to a fixed fracture square…

Algebraic Topology · Mathematics 2022-10-20 A. Ronan

We bound the higher-order Dehn functions and other filling invariants of certain Carnot groups using approximation techniques. These groups include the higher-dimensional Heisenberg groups, jet groups, and central products of two-step…

Group Theory · Mathematics 2011-03-24 Robert Young

Let $A$ be a finite subset of an abelian group $G$, and suppose that $|A+A|\leq K|A|$. We show that for any $\epsilon>0$, there exists a constant $C_\epsilon$ such that $A$ can be covered by at most $\exp(C_\epsilon \log(2K)^{1+\epsilon})$…

Number Theory · Mathematics 2026-03-02 Rushil Raghavan

We show that the torsion-free rank of $H_i(M, \mathbb{Z}_p)$ has finite upper bound for $i \leq m$, where $M$ runs through the pro-$p$ subgroups of finite index in a pro-$p$ group $G$ that is (nilpotent of class $c$)-by-abelian such that $…

Group Theory · Mathematics 2025-10-02 Dessislava H. Kochloukova , Aline G. S. Pinto

We develop a method to show that some (abstract) groups can be embedded into a free pro-$p$ group. In particular, we show that a finitely generated subgroup of a free $\mathbb Q$-group can be embedded into a free pro-$p$ group for almost…

Group Theory · Mathematics 2026-02-05 Andrei Jaikin-Zapirain

We show that uniform approximate lattices in nilpotent Lie groups are subsets of model sets. This extends a theorem due to Yves Meyer about quasicrystals in Euclidean spaces. To do so we study relatively dense subsets of simply connected…

Group Theory · Mathematics 2020-04-02 Simon Machado

The notion of bounded FC-nilpotent group is introduced and it is shown that any such group is nilpotent-by-finite, generalizing a result of Neumann on bounded FC-groups.

Group Theory · Mathematics 2017-08-08 Nadja Hempel , Daniel Palacin

In this article we extend results of Zomorrodian to determine upper bounds for the order of a nilpotent group of automorphisms of a complex $d$-dimensional family of compact Riemann surfaces, where $d \geqslant 1.$ We provide conditions…

Algebraic Geometry · Mathematics 2021-05-20 Sebastián Reyes-Carocca

We prove a Kazhdan-Margulis-Zassenhaus lemma for Hilbert geometries. More precisely, in every dimension $n$ there exists a constant $\varepsilon_n > 0$ such that, for any properly open convex set $\O$ and any point $x \in \O$, any discrete…

Geometric Topology · Mathematics 2013-02-12 Mickaël Crampon , Ludovic Marquis

In this article, we study geometric properties of nilpotent groups. We find a geometric criterion for the word problem for the finitely generated free nilpotent groups. By geometric criterion, we mean a way to determine whether two words…

Group Theory · Mathematics 2021-06-02 Ruslan Magdiev , Artem Semidetnov