Combination of locally quasiconvex hyperbolic TDLC groups and Cannon-Thurston maps

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Datta, Swarnali, Mandal, Arunava, Tomar, Ravi
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915757684686848
author Datta, Swarnali
Mandal, Arunava
Tomar, Ravi
author_facet Datta, Swarnali
Mandal, Arunava
Tomar, Ravi
contents In this article, we study acylindrical graphs of groups, local quasiconvexity, and Cannon-Thurston maps in the setting of totally disconnected locally compact (TDLC) hyperbolic groups, extending several fundamental notions and results from discrete hyperbolic groups to this broader context. Leveraging Dahmani's technique and a topological characterization of hyperbolic TDLC groups in terms of uniform convergence groups given by Carette-Dreesen, we prove a combination theorem for an acylindrical graph of hyperbolic TDLC groups and give an explicit construction of the Gromov boundary of the fundamental group of the given graph of groups. Using the description of the Gromov boundary, we prove our main result: a combination theorem for an acylindrical graph of locally quasiconvex hyperbolic TDLC groups. Further, we generalise the work of Mosher, proving the existence of quasiisometric sections for a given short exact sequence of hyperbolic TDLC groups. This leads us to prove the existence of a Cannon-Thurston map for a normal hyperbolic subgroup of a hyperbolic TDLC group, generalising a theorem of Mj.
format Preprint
id arxiv_https___arxiv_org_abs_2601_19358
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Combination of locally quasiconvex hyperbolic TDLC groups and Cannon-Thurston maps
Datta, Swarnali
Mandal, Arunava
Tomar, Ravi
Group Theory
Primary 20F65, 20F67, Secondary 22D05
In this article, we study acylindrical graphs of groups, local quasiconvexity, and Cannon-Thurston maps in the setting of totally disconnected locally compact (TDLC) hyperbolic groups, extending several fundamental notions and results from discrete hyperbolic groups to this broader context. Leveraging Dahmani's technique and a topological characterization of hyperbolic TDLC groups in terms of uniform convergence groups given by Carette-Dreesen, we prove a combination theorem for an acylindrical graph of hyperbolic TDLC groups and give an explicit construction of the Gromov boundary of the fundamental group of the given graph of groups. Using the description of the Gromov boundary, we prove our main result: a combination theorem for an acylindrical graph of locally quasiconvex hyperbolic TDLC groups. Further, we generalise the work of Mosher, proving the existence of quasiisometric sections for a given short exact sequence of hyperbolic TDLC groups. This leads us to prove the existence of a Cannon-Thurston map for a normal hyperbolic subgroup of a hyperbolic TDLC group, generalising a theorem of Mj.
title Combination of locally quasiconvex hyperbolic TDLC groups and Cannon-Thurston maps
topic Group Theory
Primary 20F65, 20F67, Secondary 22D05
url https://arxiv.org/abs/2601.19358