Properties of topological spaces

Locally Hausdorff space

In mathematics, in the field of topology, a topological space is said to be locally Hausdorff if every point has an open neighbourhood that is a Hausdorff space under the subspace topology. Here are some facts: * Every Hausdorff space is locally Hausdorff. * Every locally Hausdorff space is T1. * There are locally Hausdorff spaces where a sequence has more than one limit. This can never happen for a Hausdorff space. * The bug-eyed line is locally Hausdorff (it is in fact locally metrizable) but not Hausdorff. * The etale space for the sheaf of differentiable functions on a differential manifold is not Hausdorff, but it is locally Hausdorff. * A T1 space need not be locally Hausdorff; an example of this is an infinite set given the cofinite topology. * Let X be a set given the particular point topology. Then X is locally Hausdorff at precisely one point. From the last example, it will follow that a set (with more than one point) given the particular point topology is not a topological group. Note that if x is the 'particular point' of X, and y is distinct from x, then any set containing y that doesn't also contain x inherits the discrete topology and is therefore Hausdorff. However, no neighbourhood of y is actually Hausdorff so that the space cannot be locally Hausdorff at y. * If G is a topological group that is locally Hausdorff at x for some point x of G, then G is Hausdorff. This follows from the fact that if y is a point of G, there exists a homeomorphism from G to itself carrying x to y, so G is locally Hausdorff at every point, and is therefore T1 (and T1 topological groups are Hausdorff). (Wikipedia).

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An introduction to the Gromov-Hausdorff distance

Title: An introduction to the Gromov-Hausdorff distance Abstract: We give a brief introduction to the Hausdorff and Gromov-Hausdorff distances between metric spaces. The Hausdorff distance is defined on two subsets of a common metric space. The Gromov-Hausdorff distance is defined on any

From playlist Tutorials

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Hausdorff Example 1: Cofinite Topology

Point Set Topology: We recall the notion of a Hausdorff space and consider the cofinite topology as a source of non-Hausdorff examples. We also note that this topology is always compact.

From playlist Point Set Topology

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Hausdorff Example 3: Function Spaces

Point Set Topology: For a third example, we consider function spaces. We begin with the space of continuous functions on [0,1]. As a metric space, this example is Hausdorff, but not complete. We consider Cauchy sequences and a possible completion.

From playlist Point Set Topology

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MAST30026 Lecture 11: Hausdorff spaces (Part 1)

I introduced the Hausdorff condition, proved some basic properties, discussed the "real line with a double point" as an example of a non-Hausdorff space, proved that a compact subspace of a Hausdorff space is closed, and that continuous bijections from compact to Hausdorff spaces are homeo

From playlist MAST30026 Metric and Hilbert spaces

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Algebraic Topology - 1 - Compact Hausdorff Spaces (a Review of Point-Set Topology)

This is mostly a review point set topology. In general it is not true that a bijective continuous map is invertible (you need to worry about the inverse being continuous). In the case that your spaces are compact hausdorff this is true! We prove this in this video and review necessary fac

From playlist Algebraic Topology

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Hausdorff School: Lecture by Jean-Pierre Bourguignon

Inauguration of the Hausdorff School The “Hausdorff School for Advanced Studies in Mathematics” is an innovative new program for postdocs by the Hausdorff Center. The official inauguration took place on October 20, 2015. Lecture by Jean-Pierre Bourguignon on "Sound, Shape, and Harmony –

From playlist Inauguration of Hausdorff School 2015

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Hausdorff Center for Mathematics

The Hausdorff Center for Mathematics (HCM) capitalizes on a broad vision of mathematics, ranging from pure mathematics, to contributions to quantative modeling in economics and the natural sciences, to industrial applications. HCM strives to serve the international mathematical community a

From playlist Hausdorff Center goes public

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Hausdorff School: Introduction by Karl-Theodor Sturm

Presentation of the Hausdorff School by Karl-Theodor Sturm, coordinator of the Hausdorff Center. The “Hausdorff School for Advanced Studies in Mathematics” is an innovative new program for postdocs by the Hausdorff Center. The official inauguration took place on October 20, 2015.

From playlist Inauguration of Hausdorff School 2015

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MAST30026 Lecture 12: Function spaces (Part 3)

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From playlist MAST30026 Metric and Hilbert spaces

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MAST30026 Lecture 12: Function spaces (Part 4)

We completed the proof that the adjunction property holds for the space of continuous functions from a locally compact Hausdorff space, reminded ourselves of some of the immediate consequences of this theorem, and then began motivating the construction of a metric on function spaces. Lect

From playlist MAST30026 Metric and Hilbert spaces

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Sergey Dorogovtsev - Complex network approach to evolving manifolds and simplicial complexes

https://indico.math.cnrs.fr/event/3475/attachments/2180/2574/Dorogovtsev_GomaxSlides.pdf

From playlist Google matrix: fundamentals, applications and beyond

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Schemes 5: Definition of a scheme

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From playlist Algebraic geometry II: Schemes

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MAST30026 Lecture 18: Banach spaces (Part 1)

There are many Lipschitz equivalent metrics on Euclidean space, apart from the sup-metric (which we have successfully generalised to function spaces) there are also metrics defined using sums. To generalise those, we need integrals, and the resulting theory leads to Banach spaces. In this

From playlist MAST30026 Metric and Hilbert spaces

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Geometry of Surfaces - Topological Surfaces Lecture 1 : Oxford Mathematics 3rd Year Student Lecture

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From playlist Oxford Mathematics Student Lectures - Geometry of Surfaces

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What is a Manifold? Lesson 6: Topological Manifolds

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From playlist What is a Manifold?

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Fitting a manifold to noisy data by Hariharan Narayanan

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From playlist The Theoretical Basis of Machine Learning 2018 (ML)

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Geometry of Surfaces - Topological Surfaces Lecture 2 : Oxford Mathematics 3rd Year Student Lecture

This is the second of four lectures from Dominic Joyce's 3rd Year Geometry of Surfaces course. The four lectures cover topological surfaces and conclude with a big result, namely the classification of surfaces. This lectures covers building topological surfaces by gluing sides of polygons.

From playlist Oxford Mathematics Student Lectures - Geometry of Surfaces

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Hausdorff School für Mathematik-Nachwuchs eröffnet

Die Hausdorff School ist ein neuartiges, strukturiertes Ausbildungsprogramm für promovierte Nachwuchswissenschaftler, errichtet vom Hausdorff Center for Mathematics der Universität Bonn. Vor dem Festakt sprach uni-bonn.tv mit dem Rektor der Universität, Prof. Dr. Michael Hoch. Team: Marcu

From playlist Inauguration of Hausdorff School 2015

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Introduction to Scalar Curvature and Convergence - Christina Sormani

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From playlist Mathematics

Related pages

Topological space | Particular point topology | Non-Hausdorff manifold | Mathematics | Subspace topology | Topology | Sheaf (mathematics) | T1 space | Hausdorff space | Topological group | Open set