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Related papers: Non-Hausdorff Manifolds via Adjunction Spaces

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In this paper, as a continuation of [30], we consider the Gromov-Hausdorff convergence and collapsing in the family of compact Riemannian manifolds with boundary satisfying lower bounds on the sectional curvatures of interior manifolds,…

Differential Geometry · Mathematics 2025-04-09 Takao Yamaguchi , Zhilang Zhang

Let $X$ be a compact Gromov-Hausdorff limit space of a collapsing sequence of compact $n$-manifolds, $M_i$, of Ricci curvature $\text{Ric}_{M_i}\ge -(n-1)$ and all points in $M_i$ are $(\delta,\rho)$-local rewinding Reifenberg points, or…

Differential Geometry · Mathematics 2025-04-17 Xiaochun Rong

We construct non-trapping asymptotically hyperbolic manifolds with boundary conjugate points but no interior conjugate points.

Differential Geometry · Mathematics 2019-12-11 Nikolas Eptaminitakis , C. Robin Graham

We construct a one dimensional, second countable, simply connected manifold that exhibits a single non Hausdorff fiber, sufficient to destroy the fundamental properties of classical covering space theory. The space, called the line with k…

General Topology · Mathematics 2025-07-01 Abhiram Sripat

We give an analog of triangle comparison for Kaehler manifolds with a lower bound on the holomorphic bisectional curvature. We show that the condition passes to noncollapsed Gromov-Hausdorff limits. We discuss tangent cones and singular…

Differential Geometry · Mathematics 2021-01-26 John Lott

We combine Freedman's topology with Eliashberg's holomorphic theory to construct Stein neighborhood systems in complex surfaces, and use these to study various notions of convexity and concavity. Every tame, topologically embedded 2-complex…

Geometric Topology · Mathematics 2023-09-22 Robert E. Gompf

An asymptotically AdS geometry connecting two or more boundaries is given by a entangled state, that can be expanded in the product basis of the Hilbert spaces of each CFT living on the boundaries. We derive a prescription to compute this…

High Energy Physics - Theory · Physics 2023-08-16 Marcelo Botta Cantcheff

In this article, we construct countably many mutually non-isotopic diffeomorphisms of some closed non simply-connected 4-manifolds that are homotopic to but not isotopic to the identity, by surgery along $\Theta$-graphs. As corollaries of…

Geometric Topology · Mathematics 2023-02-24 Tadayuki Watanabe

We study the Hausdorff and the box dimensions of closed invariant subsets of the space of pointed trees, equipped with a pseudogroup action. This pseudogroup dynamical system can be regarded as a generalization of a shift space. We show…

Dynamical Systems · Mathematics 2021-12-22 Olga Lukina

A generalized-homology bordism-theory is constructed, such that for certain manifold homotopy stratified sets (MHSS; Quinn-spaces) homeomorphism-invariant geometric fundamental-classes exist. The construction combines three ideas: Firstly,…

Algebraic Topology · Mathematics 2023-10-16 Martin Rabel

We generalize the first author's construction of intersection spaces to the case of stratified pseudomanifolds of stratification depth 1 with twisted link bundles, assuming that each link possesses an equivariant Moore approximation for a…

Algebraic Topology · Mathematics 2016-07-21 Markus Banagl , Bryce Chriestenson

The purpose of this paper is to survey the possible topologies of branching space-times, and, in particular, to refute the popular notion in the literature that a branching space-time requires a non-Hausdorff topology.

General Relativity and Quantum Cosmology · Physics 2009-11-11 Gordon McCabe

The aim of this paper is to study pointed Gromov-Hausdorff Convergence of sequences of K\"ahler submanifolds of a fixed K\"ahler ambient space. Our result shows that lower bounds on the scalar curvature imply convergence to a smooth…

Differential Geometry · Mathematics 2024-01-10 Claudio Arezzo , Chao Li , Andrea Loi

We analyze the relationship between Hausdorffness and homogeneity in the frame of manifolds, not confined to be Hausdorff. We exhibit examples of homogeneous non-Hausdorff manifolds and prove that a Lindel\"of homogeneous manifold is…

General Topology · Mathematics 2012-02-21 Mathieu Baillif , Alexandre Gabard

In this paper we consider the problem of characterization of topological spaces that embed into countably compact Hausdorff spaces. We study the separation axioms of subspaces of countably compact Hausdorff spaces and construct an example…

General Topology · Mathematics 2019-06-12 Taras Banakh , Serhii Bardyla , Alex Ravsky

We consider the duality between General Relativity and the theory of Einstein algebras, in the extended setting where one permits non-Hausdorff manifolds. We show that the duality breaks down, and then go on to discuss a sense in which…

History and Philosophy of Physics · Physics 2023-10-24 Jingyi Wu , James Owen Weatherall

We develop two new methods of constructing sequences of manifolds with positive scalar curvature that converge in the Gromov-Hausdorff and Intrinsic Flat sense to limit spaces with "pulled regions". The examples created rigorously within…

Metric Geometry · Mathematics 2022-01-14 J. Basilio , C. Sormani

In a recent paper the authors classified differentiable structures on the non-Hausdorff one-dimensional manifold $\mathbb{L}$ called the line with two origins which is obtained by gluing two copies of the real line $\mathbb{R}$ via the…

Differential Geometry · Mathematics 2025-07-08 Mykola Lysynskyi , Sergiy Maksymenko

Consider a 3$-$dimensional manifold $N$ obtained by gluing a finite number of ideal hyperbolic tetrahedra via isometries along their faces. By varying the isometry type of each tetrahedron but keeping fixed the gluing pattern we define a…

Geometric Topology · Mathematics 2010-07-15 Charalampos Charitos , Ioannis Papadoperakis

For an oriented manifold $M$ whose dimension is less than $4$, we use the contractibility of certain complexes associated to its submanifolds to cut $M$ into simpler pieces in order to do local to global arguments. In particular, in these…

Algebraic Topology · Mathematics 2019-08-02 Sam Nariman