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Related papers: Extensions of finitely generated Veech groups

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Let $G$ be a Lie group, with an invariant non-degenerate symmetric bilinear form on its Lie algebra, let $\pi$ be the fundamental group of an orientable (real) surface $M$ with a finite number of punctures, and let $\bold C$ be a family of…

dg-ga · Mathematics 2008-02-03 K. Guruprasad , J. Huebschmann , L. Jeffrey , A. Weinstein

We show that for any closed surface of genus greater than one and for any finite weighted graph filling the surface, there exists a hyperbolic metric which realizes the least Dirichlet energy harmonic embedding of the graph among a fixed…

Differential Geometry · Mathematics 2020-07-27 Toru Kajigaya , Ryokichi Tanaka

Let $\mathcal G$ denote the space of finitely generated marked groups. We give equivalent characterizations of closed subspaces $\mathcal S\subseteq \mathcal G$ satisfying the following zero-one law: for any sentence $\sigma$ in the…

Group Theory · Mathematics 2022-09-27 D. Osin

In this paper, we investigate finitely generated groups of isometries of CAT(0) spaces containing some central hyperbolic isometry, and study CAT(0) groups. We show that every CAT(0) group $\Gamma$ has the semi-direct product structure…

Group Theory · Mathematics 2016-07-11 Tetsuya Hosaka

We refine Feighn--Handel's results on subgroups of mapping tori of free groups to the special case of free-by-cyclic groups. We use these refinements to show that any finitely generated free-by-cyclic group embeds in a {finitely generated…

Group Theory · Mathematics 2026-04-23 Marco Linton

In this article, we have constructed an interesting type of generalized Schottky group, named as Fuchsian Schottky group of arbitrary finite rank, in the context of the classical Schottky group (i.e., Schottky curves which are Euclidean…

Differential Geometry · Mathematics 2024-01-01 Absos Ali Shaikh , Uddhab Roy

In the first part of this work we explore the geometry of infinite type surfaces and the relationship between its convex core and space of ends. In particular, we show that a geodesically complete hyperbolic surface is made up of its convex…

Geometric Topology · Mathematics 2019-02-20 Ara Basmajian , Dragomir Saric

We prove that the fundamental group of a finite graph of convergence groups with parabolic edge groups is a convergence group. Using this result, under some mild assumptions, we prove a combination theorem for a graph of convergence groups…

Group Theory · Mathematics 2022-02-08 Ravi Tomar

We show that if G is an infinitely generated locally (polycyclic-by-finite) group with cohomology almost everywhere finitary, then every finite subgroup of G acts freely and orthogonally on some sphere.

Group Theory · Mathematics 2008-03-19 Martin Hamilton

Let $ G $ be a real simple linear connected Lie group of real rank one. Then, $ X := G/K $ is a Riemannian symmetric space with strictly negative sectional curvature. By the classification of these spaces, $X$ is a real/complex/quaternionic…

Differential Geometry · Mathematics 2017-12-01 Gilles Becker

Given a complex of groups $G(\mathcal{Y}) = (G_\sigma, \psi_a, g_{a,b})$ where all $G_\sigma$ are relatively hyperbolic, the $\psi_a$ are inclusions of full relatively quasiconvex subgroups, and the universal cover $X$ is CAT$(0)$ and…

Group Theory · Mathematics 2025-10-06 Darius Alizadeh

We prove that finitely generated purely loxodromic subgroups of a right-angled Artin group $A(\Gamma)$ fulfill equivalent conditions that parallel characterizations of convex cocompactness in mapping class groups $\text{Mod}(S)$. In…

Group Theory · Mathematics 2016-03-10 Thomas Koberda , Johanna Mangahas , Samuel J. Taylor

We provide sufficient conditions for two subgroups of a hierarchically hyperbolic group to generate an amalgamated free product over their intersection. The result applies in particular to certain geometric subgroups of mapping class groups…

Group Theory · Mathematics 2026-01-07 Giorgio Mangioni

Ratner's theorem implies topological rigidity of immersed totally geodesic subspaces of noncompact type in finite-volume locally symmetric spaces. In higher rank and infinite volume, however, counter-examples to this rigidity have remained…

Geometric Topology · Mathematics 2026-02-18 Subhadip Dey , Hee Oh

We prove that every finite subgroup of $GL_{2}(\mathbb{R})$ can be realized as the Veech group of some translation surface.

Dynamical Systems · Mathematics 2010-05-20 Asaf Hadari

We construct finitely generated groups with strong fixed point properties. Let $\mathcal{X}_{ac}$ be the class of Hausdorff spaces of finite covering dimension which are mod-$p$ acyclic for at least one prime $p$. We produce the first…

Group Theory · Mathematics 2014-11-11 G. Arzhantseva , M. R. Bridson , T. Januszkiewicz , I. J. Leary , A. Minasyan , J. Swiatkowski

In this paper, for each $k\in \mathbb{N}$, we define a complex $\Gamma_k(S)$ for an infinite-type surface $S$ with non-planar ends, which serves as an analog of the Hatcher-Thurston complex for the infinite-type setting. We show that…

Geometric Topology · Mathematics 2026-02-27 Manvendra Somvanshi

Let $S$ be a surface of negative Euler characteristic and consider a finite filling collection $\Gamma$ of closed curves on $S$ in minimal position. An observation of Foulon and Hasselblatt shows that $PT(S) \setminus \hat{\Gamma}$ is a…

Geometric Topology · Mathematics 2022-02-08 Tommaso Cremaschi , José Andrés Rodríguez Migueles , Andrew Yarmola

A seminal result in geometric group theory is that a 1-ended hyperbolic group has a locally connected visual boundary. As a consequence, a 1-ended hyperbolic group also has a path connected visual boundary. In this paper, we study when this…

Group Theory · Mathematics 2019-10-18 Michael Ben-Zvi

We introduce a class of countable groups by some abstract group-theoretic conditions. It includes linear groups with finite amenable radical and finitely generated residually finite groups with some non-vanishing $\ell^2$-Betti numbers that…

Group Theory · Mathematics 2018-07-20 Uri Bader , Alex Furman , Roman Sauer