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Under the definition of Ricci curvature bounded below for Alexandrov spaces introduced by Zhang-Zhu, we generalize a result by Colding that an n dimentional manifold with Ricci curvature greater or equal to n minus 1 and volume close to…

Metric Geometry · Mathematics 2015-03-27 Zisheng Hu , Le Yin

Let $X$ be a space. A space $Y$ is called an extension of $X$ if $Y$ contains $X$ as a dense subspace. For an extension $Y$ of $X$ the subspace $Y\backslash X$ of $Y$ is called the remainder of $Y$. Two extensions of $X$ are said to be…

General Topology · Mathematics 2012-07-26 M. R. Koushesh

In this paper we examine two basic topological properties of partial metric spaces, namely compactness and completeness. Our main result claims that in these spaces compactness is equivalent to sequential compactness. We also show that…

General Topology · Mathematics 2022-02-01 Dariusz Bugajewski , Piotr Maćkowiak , Ruidong Wang

Abstract. In this paper we prove several rigidity theorems related to and including Lytchak's problem. The focus is on Alexandrov spaces with \curv\geq1, nonempty boundary, and maximal radius \frac{\pi}{2}. We exhibit many such spaces that…

Differential Geometry · Mathematics 2022-11-09 Karsten Grove , Peter Petersen

We study an order relation on the fibers of a continuous map and its application to the study of the structure of compact spaces of uncountable weight.

General Topology · Mathematics 2010-01-26 Antonio Avilés , Ondrej F. K. Kalenda

In this paper we give a new proof for an almost isometry theorem in Alexandrov spaces with curvature bounded below.

Differential Geometry · Mathematics 2010-06-29 Xiaole Su , Hongwei Sun , Yusheng Wang

We study stratification, that is the classification of localizing tensor ideal subcategories by geometric means, in the context of Kasparov's equivariant KK-theory of C*-algebras. We introduce a straightforward countable analog of the…

K-Theory and Homology · Mathematics 2026-01-21 Ivo Dell'Ambrogio , Rubén Martos

We define a notion of relative fundamental class that applies to moduli spaces in gauge theory and in symplectic Gromov-Witten theory. For universal moduli spaces over a parameter space, the relative fundamental class specifies an element…

Symplectic Geometry · Mathematics 2018-04-27 Eleny-Nicoleta Ionel , Thomas H. Parker

The complement of an arrangement of hyperplanes in $\mathbb C^n$ has a natural bordification to a manifold with corners formed by removing (or "blowing up") tubular neighborhoods of the hyperplanes and certain of their intersections. When…

Geometric Topology · Mathematics 2021-04-07 Michael W. Davis , Jingyin Huang

We present a higher-categorical generalization of the "Karoubi envelope" construction from ordinary category theory, and prove that, like the ordinary Karoubi envelope, our higher Karoubi envelope is the closure for absolute limits. Our…

Category Theory · Mathematics 2025-04-07 Davide Gaiotto , Theo Johnson-Freyd

We establish results about algebraic shifting of simplicial complexes and use them to compare different shifting operations. In particular, we show that each shifting operation does not decrease the number of facets, and that the exterior…

Commutative Algebra · Mathematics 2007-05-23 Uwe Nagel , Tim Roemer , Natale Paolo Vinai

The aim of these lecture notes is, after having quickly described various compactifications of the Teichm\"{u}ller space of a compact connected oriented surface minus finitely many points, to give a construction, by the equivariant Gromov…

Complex Variables · Mathematics 2016-08-16 Frédéric Paulin

In this paper, we approach the question if some of the separation axioms are equivalent in the class of asymmetric normed spaces. In particular, we make a remark on a known theorem which states that every $T_1$ asymmetric normed space with…

General Topology · Mathematics 2019-05-10 Victor Donjuán , Natalia Jonard-Pérez

Replacing configurations of points by configurations of tubular neighbourhoods (or discs) in a manifold, we are able to define a natural scanning map that is equivariant under the action of the diffeomorphism group of the manifold. We also…

Algebraic Topology · Mathematics 2017-05-17 Richard Manthorpe , Ulrike Tillmann

We announce a solution to several enumeration problems in topology of surfaces. This includes an enumeration of homotopy classes of sections of locally trivial fiber bundles over surfaces and a computation of non-abelian 1-cohomology of…

Geometric Topology · Mathematics 2008-10-31 Vladimir Turaev

We consider the category of all locally Lipschitz contractible metric spaces and all locally Lipschitz maps, which is a wide class of metric spaces, including all finite dimensional Alexandrov spaces and all CAT spaces. We also consider the…

Algebraic Topology · Mathematics 2015-10-27 Ayato Mitsuishi

I extend the framework of rigid analytic geometry to the setting of algebraic geometry relative to monoids, and study the associated notions of separated, proper, and overconvergent morphisms. The category of affine manifolds embeds as a…

Algebraic Geometry · Mathematics 2015-05-29 Andrew W. Macpherson

A uniform space is a topological space together with some additional structure which allows one to make sense of uniform properties such as completeness or uniform convergence. Motivated by previous work of J. Rivera-Letelier, we give a new…

Number Theory · Mathematics 2007-05-23 Matthew Baker

We obtain a topological and equivariant classification of closed, connected three-dimensional Alexandrov spaces admitting a local isometric circle action. We show, in particular, that such spaces are homeomorphic to connected sums of some…

Differential Geometry · Mathematics 2020-10-21 Fernando Galaz-Garcia , Jesús Núñez-Zimbrón

In this work we describe horofunction compactifications of metric spaces and finite dimensional real vector spaces through asymmetric metrics and asymmetric polyhedral norms by means of nonstandard methods, that is, ultrapowers of the…

Metric Geometry · Mathematics 2023-05-05 Corina Ciobotaru , Linus Kramer , Petra Schwer