Results 31 to 40 of about 119 (107)

Gromov hyperbolic groups and the Macaev norm [PDF]

Pacific Journal of Mathematics, 2006
Let \(\Gamma\) be a Gromov hyperbolic group with a finite set \(A\) of generators. One can consider three quantities: the Coornaert-Papadopoulos topological entropy \(h_{top}(\Sigma(\infty))\) of the subshift associated to \((\Gamma,A)\), Voiculescu's invariant \(k^-_\infty(\lambda_A)\), and the growth entropy \(\text{gr}(\Gamma,A)\). The author proves
openaire   +2 more sources

Exactness and the topology of the space of invariant random equivalence relations

Proceedings of the London Mathematical Society, Volume 132, Issue 5, May 2026.
Abstract We characterize exactness of a countable group Γ$\Gamma$ in terms of invariant random equivalence relations (IREs) on Γ$\Gamma$. Specifically, we show that Γ$\Gamma$ is exact if and only if every weak limit of finite IREs is an amenable IRE.
Héctor Jardón‐Sánchez, Sam Mellick, Antoine Poulin, Konrad Wróbel   +3 more
wiley   +1 more source

Non‐amenability of mapping class groups of infinite‐type surfaces and graphs

Bulletin of the London Mathematical Society, Volume 58, Issue 4, April 2026.
Abstract This paper completely determines the non‐amenability of the mapping class groups of infinite‐type surfaces, the mapping class groups of locally finite infinite graphs of higher ranks, gives an example of non‐amenable stabiliser of a point at infinity of a coarsely bounded generated hyperbolic Polish group, and exhibits a class of mapping class
Yusen Long
wiley   +1 more source

Graphical small cancellation and hyperfiniteness of boundary actions

Journal of the London Mathematical Society, Volume 113, Issue 4, April 2026.
Abstract We study actions of (infinitely presented) graphical small cancellation groups on the Gromov boundaries of their coned‐off Cayley graphs. We show that a class of graphical small cancellation groups, including (infinitely presented) classical small cancellation groups, admit hyperfinite boundary actions, more precisely, the orbit equivalence ...
Chris Karpinski, Damian Osajda, Koichi Oyakawa   +2 more
wiley   +1 more source

Uniform growth in small cancellation groups

Journal of the London Mathematical Society, Volume 113, Issue 4, April 2026.
Abstract An open question asks whether every group acting acylindrically on a hyperbolic space has uniform exponential growth. We prove that the class of groups of uniform uniform exponential growth acting acylindrically on a hyperbolic space is closed under taking certain geometric small cancellation quotients.
Xabier Legaspi, Markus Steenbock
wiley   +1 more source

Sublinear bilipschitz equivalence and the quasiisometric classification of solvable Lie groups

Journal of the London Mathematical Society, Volume 113, Issue 4, April 2026.
Abstract We prove a product theorem for sublinear bilipschitz equivalences which generalizes the classical work of Kapovich, Kleiner, and Leeb on quasiisometries between product spaces. We employ our product theorem to distinguish up to quasiisometry certain families of solvable groups which share the same dimension, cone‐dimension and Dehn function ...
Ido Grayevsky, Gabriel Pallier
wiley   +1 more source

Circle packings, renormalizations, and subdivision rules

Proceedings of the London Mathematical Society, Volume 132, Issue 4, April 2026.
Abstract In this paper, we use iterations of skinning maps on Teichmüller spaces to study circle packings and develop a renormalization theory for circle packings whose nerves satisfy certain subdivision rules. We characterize when the skinning map has bounded image.
Yusheng Luo, Yongquan Zhang
wiley   +1 more source

Limits of cubic differentials and buildings

Proceedings of the London Mathematical Society, Volume 132, Issue 4, April 2026.
Abstract In the Labourie–Loftin parameterization of the Hitchin component of surface group representations into SL(3,R)$\mathrm{SL}(3,\mathbb {R})$, we prove an asymptotic formula for holonomy along rays in terms of local invariants of the holomorphic differential defining that ray.
John Loftin, Andrea Tamburelli, Michael Wolf   +2 more
wiley   +1 more source

Gromov hyperbolic spaces

Expositiones Mathematicae, 2005
This is a mini monograph on Gromov hyperbolic spaces, which are not necessarily geodesic or proper. As the author notes, the purpose of the article is to give a fairly detailed treatment of the basic theory of hyperbolic spaces more general than proper and geodesic.
openaire   +1 more source

Graph potentials and topological quantum field theories

Proceedings of the London Mathematical Society, Volume 132, Issue 4, April 2026.
Abstract We introduce a new functional equation in birational geometry, whose solutions can be used to construct two‐dimensional topological quantum field theories (2d TQFTs), infinite‐dimensional in many interesting examples. The solutions of the equation give rise to a hierarchy of graph potentials, which, in the simplest setup, are Laurent ...
Pieter Belmans, Sergey Galkin, Swarnava Mukhopadhyay   +2 more
wiley   +1 more source