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Related papers: Isospectral Alexandrov Spaces

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We construct the first examples of continuous families of isospectral Riemannian metrics that are not locally isometric on closed manifolds, more precisely, on $S^n\times T^m$, where $T^m$ is a torus of dimension $m\ge 2$ and $S^n$ is a…

We show that any n-dimensional nonnegatively curved Alexandrov space with the maximal possible number of extremal points is isometric to a quotient space of Euclidean n -space by an action of a crystallographic group. We describe all such…

Metric Geometry · Mathematics 2015-06-03 Nina Lebedeva

We prove that sufficiently collapsed, closed and irreducible three-dimensional Alexandrov spaces are modeled on one of the eight three-dimensional Thurston geometries. This extends a result of Shioya and Yamaguchi, originally formulated for…

Differential Geometry · Mathematics 2020-05-21 Fernando Galaz-Garcia , Luis Guijarro , Jesús Núñez-Zimbrón

In this paper we describe recent results on explicit construction of lens spaces that are not strongly isospectral, yet they are isospectral on $p$-forms for every $p$. Such examples cannot be obtained by the Sunada method. We also discuss…

Differential Geometry · Mathematics 2016-02-25 Emilio A. Lauret , Roberto J. Miatello , Juan Pablo Rossetti

We find conditions under which the pretangent spaces to general metric spaces have the nonpositive Aleksandrov curvature or nonnegative one. The infinitesimal structure of general metric cpaces with Busemann convex pretangent spaces is also…

Metric Geometry · Mathematics 2013-01-21 Viktoriia Bilet , Oleksiy Dovgoshey

We develop two new tools for use in Alexandrov geometry: a theory of ramified orientable double covers and a particularly useful version of the Slice Theorem for actions of compact Lie groups. These tools are applied to the classification…

Differential Geometry · Mathematics 2020-01-23 John Harvey , Catherine Searle

We develop a new concept of non-positive curvature for metric spaces, based on intersection patterns of closed balls. In contrast to the synthetic approaches of Alexandrov and Buesemann, our concept also applies to metric spaces that might…

Metric Geometry · Mathematics 2020-01-29 Parvaneh Joharinad , Jürgen Jost

We use two of the most fruitful methods for constructing isospectral manifolds, the Sunada method and the torus action method, to construct manifolds whose Dirichlet-to-Neumann operators are isospectral at all frequencies. The manifolds are…

Differential Geometry · Mathematics 2018-09-03 Carolyn Gordon , Peter Herbrich , David Webb

We prove that Alexandrov spaces $X$ of nonnegative curvature have Markov type 2 in the sense of Ball. As a corollary, any Lipschitz continuous map from a subset of $X$ into a 2-uniformly convex Banach space is extended as a Lipschitz…

Metric Geometry · Mathematics 2010-05-11 Shin-ichi Ohta

In this note, we study the radius of positively curved or non-negatively curved Alexandrov space with strictly convex boundary, with convexity measured by the Base-Angle defined by Alexander and Bishop. We also estimate the volume of the…

Differential Geometry · Mathematics 2018-12-07 Jian Ge , Ronggang Li

Going beyond the cohomological invariants attached to tiling spaces via inverse limit constructions, Clark and Hunton introduced shape group invariants, and showed these invariants in dimension one give new information. We show for…

Dynamical Systems · Mathematics 2015-12-21 Scott Schmieding

We study closed three-dimensional Alexandrov spaces with a lower Ricci curvature bound in the $\mathsf{CD}^*(K,N)$ sense, focusing our attention on those with positive or nonnegative Ricci curvature. First, we show that a closed…

Differential Geometry · Mathematics 2016-02-26 Qintao Deng , Fernando Galaz-Garcia , Luis Guijarro , Michael Munn

We prove that iterated spaces of directions of a limit of a noncollapsing sequence of manifolds with lower curvature bound are topologically spheres. As an application we show that for any finite dimensional Alexandrov space $X^n$ with…

Differential Geometry · Mathematics 2016-09-07 Vitali Kapovitch

We give a classification of toric anti-self-dual conformal structures on compact 4-orbifolds with positive Euler characteristic. Our proof is twistor theoretic: the interaction between the complex torus orbits in the twistor space and the…

Differential Geometry · Mathematics 2009-09-22 Dominic Wright

We consider an infinitesimal version of the Bishop-Gromov relative volume comparison condition as generalized notion of Ricci curvature bounded below for Alexandrov spaces. We prove a Laplacian comparison theorem for Alexandrov spaces under…

Differential Geometry · Mathematics 2007-09-07 Kazuhiro Kuwae , Takashi Shioya

We extend the equivariant classification results of Escher and Searle for closed, simply connected, non-negatively curved Riemannian $n$-manifolds admitting isometric isotropy-maximal torus actions to the class of such manifolds admitting…

Differential Geometry · Mathematics 2023-11-28 Zheting Dong , Christine Escher , Catherine Searle

We examine properties of equidistant sets determined by nonempty disjoint compact subsets of a compact 2-dimensional Alexandrov space (of curvature bounded below). The work here generalizes many of the known results for equidistant sets…

Metric Geometry · Mathematics 2022-05-20 Logan S. Fox , J. J. P. Veerman

Two methods of constructing infinitely many isomorphically distinct $\Cal L_p$-spaces have been published. In this article we show that these constructions yield very different spaces and in the process develop methods for dealing with…

Functional Analysis · Mathematics 2016-09-06 Dale E. Alspach

Let $M_j$ be a sequence of Riemannian manifolds with sectional curvature bound below collapsing to a compact Alexandrov space $X$ of dimension $k$. Suppose that all but finitely many points of $X$ are $(k,\delta)$-strained and that the…

Differential Geometry · Mathematics 2023-01-18 Tadashi Fujioka

In [23], Slipantschuk, Bandtlow and Just gave concrete examples of Anosov diffeomorphisms of the two-torus for which their resonances could be completely described. Their approach was based on composition operators acting on analytic…

Dynamical Systems · Mathematics 2022-12-07 Mark Pollicott , Benedict Sewell