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Related papers: Hadamard spaces with isolated flats

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We study discrete groups from the view point of a dimension gap in connection to CAT(0) geometry. Developing studies by Brady-Crisp and Bridson, we show that there exist finitely presented groups of geometric dimension 2 which do not act…

Geometric Topology · Mathematics 2014-10-01 Koji Fujiwara , Takashi Shioya , Saeko Yamagata

Any discrete action of a group on a locally compact Hadamard space extends to a topological action on the virtual boundary. Croke and Kleiner introduced a class of so-called admissible actions and associated geometric data which determine…

Metric Geometry · Mathematics 2010-11-16 Sebastian Grensing

It is well known that the Tits boundary of a proper cocompact CAT(0) space embeds into every asymptotic cone of the space. We explore the relationships between the asymptotic cones of a CAT(0) space and its boundary under both the standard…

Group Theory · Mathematics 2018-09-13 Curtis Kent , Russell Ricks

We initiate systematic study of EZ-structures (and associated boundaries) of groups acting on spaces that admit consistent and conical (equivalently, consistent and convex) geodesic bicombings. Such spaces recently drew a lot of attention…

Group Theory · Mathematics 2025-05-13 Daniel Danielski

Mahan Mitra (Mj) proved Cannon--Thurston maps exist for normal hyperbolic subgroups of a hyperbolic group. We prove that Cannon--Thurston maps do not exist for infinite normal hyperbolic subgroups of non-hyperbolic CAT(0) groups with…

Geometric Topology · Mathematics 2019-11-13 Benjamin Beeker , Matthew Cordes , Giles Gardam , Radhika Gupta , Emily Stark

Let G be a group and let M be a CAT(0) proper metric space (e.g. a simply connected complete Riemannian manifold of non-positive sectional curvature or a locally finite tree). Isometric actions of G on M are (by definition) points in the…

Group Theory · Mathematics 2007-05-23 Robert Bieri , Ross Geoghegan

We provide an analysis of the dynamics of isometries and semicontractions of metric spaces. Certain subsets of the boundary at infinity play a fundamental role and are identified completely for the standard boundaries of CAT(0)-spaces,…

Metric Geometry · Mathematics 2014-11-11 Anders Karlsson

We construct examples of flat surfaces in $\mathbb{H}^3$ which are graphs over a two-punctured horosphere and classify complete embedded flat surfaces in $\mathbb{H}^3$ with only one end and at most two isolated singularities.

Differential Geometry · Mathematics 2009-05-15 Armando V. Corro , Antonio Martinez , Francisco Milan

We consider minimal submanifolds of negatively curved spaces with small curvature. We show that in a Hadamard space with negatively pinched curvature $-C\leq K\leq -1$, complete minimal submanifolds with second fundamental form less than…

Differential Geometry · Mathematics 2023-11-27 Samuel Bronstein

Following previous work of the second author, we establish more properties of groups of circle homeomorphisms which admit invariant laminations. In this paper, we focus on a certain type of such groups-so-called pseudo-fibered groups, and…

Geometric Topology · Mathematics 2020-02-24 Juan Alonso , Hyungryul Baik , Eric Samperton

Let $G$ be a group with a non-elementary action on a (not necessarily discrete) $\tilde{A}_2$-buildings. We prove that, given a random walk on $G$, isometries in $G$ are strongly regular hyperbolic with high probability. As a consequence,…

Group Theory · Mathematics 2024-11-08 Corentin Le Bars , Jean Lécureux , Jeroen Schillewaert

In this paper, we present a geometric condition for a family of CAT(0) spaces, which ensures that the Izeki-Nayatani invariants of spaces in the family are uniformly bounded from above by a constant strictly less than 1. Each element of…

Metric Geometry · Mathematics 2010-11-09 Tetsu Toyoda

The present paper, which is partially a review, but also contains several completely new results, aims at presenting, in a unified mathematical framework, a complex and articulated lore regarding non-compact symmetric spaces, with negative…

Differential Geometry · Mathematics 2025-11-11 Ugo Bruzzo , Pietro Fré , Mario Trigiante

Given a complete CAT(0) space $X$ endowed with a geometric action of a group $\Gamma$, it is known that if $\Gamma$ contains a free abelian group of rank $n$, then $X$ contains a geometric flat of dimension $n$. We prove a converse of this…

Group Theory · Mathematics 2010-02-08 Pierre-Emmanuel Caprace , Frédéric Haglund

In this paper we provide a classification theorem for 1-dimensional boundaries of groups with isolated flats. Given a group $\Gamma$ acting geometrically on a $CAT(0)$ space $X$ with isolated flats and 1-dimensional boundary, we show that…

Group Theory · Mathematics 2018-06-27 Matthew Haulmark

We study isometric actions of compact Lie groups on complete orientable positively curved $n$-manifolds whose orbit spaces have non-empty boundary in the sense of Alexandrov geometry. In particular, we classify quotients of the unit sphere…

Differential Geometry · Mathematics 2024-02-23 Claudio Gorodski , Andreas Kollross , Burkhard Wilking

The purpose of this paper is to investigate torsion-free groups which act properly and cocompactly on CAT(0) metric spaces which have isolated flats, as defined by Hruska. Our approach is to seek results analogous to those of Sela,…

Group Theory · Mathematics 2014-10-01 Daniel Groves

The main result of this paper is that given a group $G$ acting geometrically by isometries on a CAT(0) space $X$ and a cyclic subgroup $H$ of $G$ generated by a rank-1 isometry of $X$, $H$ has bounded packing in $G$. We give two proofs of…

Group Theory · Mathematics 2015-10-27 Pranab Sardar

Let $X$ be a proper CAT(0) space and let $G$ be a cocompact group of isometries of $X$ which acts properly discontinuously. Charney and Sultan constructed a quasi-isometry invariant boundary for proper CAT(0) spaces which they called the…

Geometric Topology · Mathematics 2021-10-20 Devin Murray

If H is a flat group of automorphisms of finite rank n of a totally disconnected, locally compact group G, then each orbit of H in the metric space B(G) of compact, open subgroups of G is quasi-isometric to n-dimensional euclidean space. In…

Group Theory · Mathematics 2008-08-01 Udo Baumgartner , Günter Schlichting , George A. Willis