Fractals | Measures (measure theory) | Dimension theory | Metric geometry

Hausdorff measure

In mathematics, Hausdorff measure is a generalization of the traditional notions of area and volume to non-integer dimensions, specifically fractals and their Hausdorff dimensions. It is a type of outer measure, named for Felix Hausdorff, that assigns a number in [0,∞] to each set in or, more generally, in any metric space. The zero-dimensional Hausdorff measure is the number of points in the set (if the set is finite) or ∞ if the set is infinite. Likewise, the one-dimensional Hausdorff measure of a simple curve in is equal to the length of the curve, and the two-dimensional Hausdorff measure of a Lebesgue-measurable subset of is proportional to the area of the set. Thus, the concept of the Hausdorff measure generalizes the Lebesgue measure and its notions of counting, length, and area. It also generalizes volume. In fact, there are d-dimensional Hausdorff measures for any d ≥ 0, which is not necessarily an integer. These measures are fundamental in geometric measure theory. They appear naturally in harmonic analysis or potential theory. (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 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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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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What is the distance between two sets of points? | Hausdorff Distance

What is the distance between two sets of points is a non-trivial question that has applications all over the place, from bioinformatics and computer science to fractal geometry. In this video, I'll give a bit of motivation, introduce the delta expansion of a set and then give the distance

From playlist The New CHALKboard

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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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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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Quantitative propagation for solutions of elliptic equations – A. Logunov & E. Malinnikova – ICM2018

Partial Differential Equations | Geometry Invited Lecture 10.11 | 5.12 Quantitative propagation of smallness for solutions of elliptic equations Alexander Logunov & Eugenia Malinnikova Abstract: Let u be a solution to an elliptic equation div(A∇u)=0 with Lipschitz coefficients in ℝⁿ. Ass

From playlist Geometry

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Quantitative decompositions of Lipschitz mappings - Guy C. David

Analysis Seminar Topic: Quantitative decompositions of Lipschitz mappings Speaker: Guy C. David Affiliation: Ball State University Date: May 12, 2020 For more video please visit http://video.ias.edu

From playlist Mathematics

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Introduction to Scalar Curvature and Convergence - Christina Sormani

Emerging Topics Working Group Topic: Introduction to Scalar Curvature and Convergence Speaker: Christina Sormani Affilaition: IAS Date: October 15, 2018 For more video please visit http://video.ias.edu

From playlist Mathematics

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C. Sormani - Intrinsic Flat and Gromov-Hausdorff Convergence 1

We introduce various notions of convergence of Riemannian manifolds and metric spaces. We then survey results and open questions concerning the limits of sequences of Riemannian manifolds with uniform lower bounds on their scalar curvature. We close the course by presenting methods and the

From playlist Ecole d'été 2021 - Curvature Constraints and Spaces of Metrics

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Henry Adams (3/22/22): Gromov-Hausdorff distances, Borsuk-Ulam theorems, and Vietoris-Rips complexes

The Gromov-Hausdorff distance between two metric spaces is an important tool in geometry, but it is difficult to compute. For example, the Gromov-Hausdorff distance between unit spheres of different dimensions is unknown in nearly all cases. I will introduce recent work by Lim, Mémoli, and

From playlist Vietoris-Rips Seminar

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Fitting a manifold to noisy data by Hariharan Narayanan

DISCUSSION MEETING THE THEORETICAL BASIS OF MACHINE LEARNING (ML) ORGANIZERS: Chiranjib Bhattacharya, Sunita Sarawagi, Ravi Sundaram and SVN Vishwanathan DATE : 27 December 2018 to 29 December 2018 VENUE : Ramanujan Lecture Hall, ICTS, Bangalore ML (Machine Learning) has enjoyed tr

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

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MAST30026 Lecture 17: Integrals

I began by explaining how, in order to work with infinite-dimensional function spaces constructively, we need to use integrals. Then I defined an "integral pair", showed that the Riemann integral on a closed interval is an example, and proved that there is a product operation on integral p

From playlist MAST30026 Metric and Hilbert spaces

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Yevgeny Liokumovich (9/10/21): Urysohn width, isoperimetric inequalities and scalar curvature

There exists a positive constant c(n) with the following property. If M is a metric space, such that every ball B of radius 1 in M has Hausdorff n-dimensional measure less than c(n), then there exists a continuous map f from M to (n-1)-dimensional simplicial complex, such that every pre-im

From playlist Vietoris-Rips Seminar

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C. Sormani - Intrinsic Flat and Gromov-Hausdorff Convergence 1 (version temporaire)

We introduce various notions of convergence of Riemannian manifolds and metric spaces. We then survey results and open questions concerning the limits of sequences of Riemannian manifolds with uniform lower bounds on their scalar curvature. We close the course by presenting methods and the

From playlist Ecole d'été 2021 - Curvature Constraints and Spaces of Metrics

Related pages

Outer measure | Metric space | Lebesgue measure | Almost surely | Carathéodory's extension theorem | Volume | Potential theory | Dimension function | Brownian motion | Bounded set | Gamma function | Mathematics | N-sphere | Minkowski content | Geometric measure theory | Hausdorff dimension | Area | Rectifiable set | Metric outer measure | Harmonic analysis