Results 21 to 30 of about 72 (72)

Generalising Collins' theorem

Journal of the London Mathematical Society, Volume 112, Issue 1, July 2025.
Abstract We generalise a result of D. J. Collins on intersections of conjugates of Magnus subgroups of one‐relator groups to the context of one‐relator products of locally indicable groups.
James Howie, Hamish Short
wiley   +1 more source

Profinite rigidity for free‐by‐cyclic groups with centre

Journal of the London Mathematical Society, Volume 111, Issue 6, June 2025.
Abstract A free‐by‐cyclic group FN⋊ϕZ$F_N\rtimes _\phi \mathbb {Z}$ has non‐trivial centre if and only if [ϕ]$[\phi]$ has finite order in Out(FN)${\rm {Out}}(F_N)$. We establish a profinite rigidity result for such groups: if Γ1$\Gamma _1$ is a free‐by‐cyclic group with non‐trivial centre and Γ2$\Gamma _2$ is a finitely generated free‐by‐cyclic group ...
Martin R. Bridson, Paweł Piwek
wiley   +1 more source

Purity, ascent and periodicity for Gorenstein flat cotorsion modules

Journal of the London Mathematical Society, Volume 111, Issue 6, June 2025.
Abstract We investigate purity within the Frobenius category of Gorenstein flat cotorsion modules, which can be seen as an infinitely generated analogue of the Frobenius category of Gorenstein projective objects. As such, the associated stable category can be viewed as an alternative approach to a big singularity category, which is equivalent to Krause'
Isaac Bird
wiley   +1 more source

On profinite rigidity amongst free‐by‐cyclic groups I: The generic case

Proceedings of the London Mathematical Society, Volume 130, Issue 6, June 2025.
Abstract We prove that amongst the class of free‐by‐cyclic groups, Gromov hyperbolicity is an invariant of the profinite completion. We show that whenever G$G$ is a free‐by‐cyclic group with first Betti number equal to one, and H$H$ is a free‐by‐cyclic group which is profinitely isomorphic to G$G$, the ranks of the fibres and the characteristic ...
Sam Hughes, Monika Kudlinska
wiley   +1 more source

The Hilton–Milnor theorem in higher topoi

Bulletin of the London Mathematical Society, Volume 57, Issue 5, Page 1468-1481, May 2025.
Abstract In this note, we show that the classical theorem of Hilton–Milnor on finite wedges of suspension spaces remains valid in an arbitrary ∞$\infty$‐topos. Our result relies on a version of James' splitting proved in [Devalapurkar and Haine, Doc. Math.
Samuel Lavenir
wiley   +1 more source

The homological spectrum via definable subcategories

Bulletin of the London Mathematical Society, Volume 57, Issue 4, Page 1040-1064, April 2025.
Abstract We develop an alternative approach to the homological spectrum of a tensor‐triangulated category through the lens of definable subcategories. This culminates in a proof that the homological spectrum is homeomorphic to a quotient of the Ziegler spectrum.
Isaac Bird, Jordan Williamson
wiley   +1 more source

Twisted conjugacy in soluble arithmetic groups

Mathematische Nachrichten, Volume 298, Issue 3, Page 763-793, March 2025.
Abstract Reidemeister numbers of group automorphisms encode the number of twisted conjugacy classes of groups and might yield information about self‐maps of spaces related to the given objects. Here, we address a question posed by Gonçalves and Wong in the mid‐2000s: we construct an infinite series of compact connected solvmanifolds (that are not ...
Paula M. Lins de Araujo, Yuri Santos Rego   +1 more
wiley   +1 more source

Cluster categories for completed infinity‐gons I: Categorifying triangulations

Journal of the London Mathematical Society, Volume 111, Issue 2, February 2025.
Abstract Paquette and Yıldırım recently introduced triangulated categories of arcs in completed infinity‐gons, which are discs with an infinite closed set of marked points on their boundary. These categories have many features in common with the cluster categories associated to discs with different sets of marked points. In particular, they have (weak)
İlke Çanakçı, Martin Kalck, Matthew Pressland   +2 more
wiley   +1 more source

On the Witt group of the punctured spectrum of a regular semilocal ring

Journal of the London Mathematical Society, Volume 110, Issue 6, December 2024.
Abstract Let R$R$ be a regular semilocal ring of dimension 4q+1⩾5$4q+1\geqslant 5$ which contains 12$\frac{1}{2}$, l⩾1$l\geqslant 1$ the number of maximal ideals of R$R$ which are assumed to be all of the same height, and U$U$ the punctured spectrum of R$R$, that is, SpecR$\operatorname{Spec}R$ without the maximal ideals. We show that the Witt ring W(U)
Stefan Gille, Ivan Panin
wiley   +1 more source

Recalibrating R$\mathbb {R}$‐order trees and Homeo+(S1)$\mbox{Homeo}_+(S^1)$‐representations of link groups

Journal of Topology, Volume 17, Issue 4, December 2024.
Abstract In this paper, we study the left‐orderability of 3‐manifold groups using an enhancement, called recalibration, of Calegari and Dunfield's ‘flipping’ construction, used for modifying Homeo+(S1)$\text{Homeo}_+(S^1)$‐representations of the fundamental groups of closed 3‐manifolds.
Steven Boyer, Cameron McA. Gordon, Ying Hu   +2 more
wiley   +1 more source