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Related papers: Spaces of extremal magnitude

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We present several applications of matrix-theoretic inequalities to the magnitude of metric spaces. We first resolve an open problem by showing that the magnitude of any finite metric space of negative type is less than or equal to its…

Metric Geometry · Mathematics 2025-09-30 Kiyonori Gomi , Mark Meckes

The main result of this article is a geometric interpretation of magnitude, a real-valued invariant of metric spaces. We introduce a Euclidean embedding of a (suitable) finite metric space $X$ such that the magnitude of $X$ can be expressed…

Metric Geometry · Mathematics 2025-10-22 Karel Devriendt

In ancient Greek mathematics, magnitudes such as lengths were strictly distinguished from numbers. In modern quantity calculus, a distinction is made between quantities and scalars that serve as measures of quantities. It can be argued that…

Rings and Algebras · Mathematics 2023-01-12 Dan Jonsson

We investigate \emph{magnitude} as a new unary and strictly Pareto-compliant quality indicator for finite approximation sets to the Pareto front in multiobjective optimization. Magnitude originates in enriched category theory and metric…

Optimization and Control · Mathematics 2026-04-21 Michael T. M. Emmerich

Magnitude homology is an $\mathbf{R}^+$-graded homology theory of metric spaces that captures information on the complexity of geodesics. Here we address the question: when are two metric spaces magnitude homology equivalent, in the sense…

Metric Geometry · Mathematics 2026-02-25 Adrián Doña Mateo , Tom Leinster

In this paper we introduce the persistent magnitude, a new numerical invariant of (sufficiently nice) graded persistence modules. It is a weighted and signed count of the bars of the persistence module, in which a bar of the form $[a,b)$ in…

Algebraic Topology · Mathematics 2022-04-25 Dejan Govc , Richard Hepworth

This paper outlines a possibility for spacetime dynamics and structure, without postulating a metric ab initio. In this model, the closer an object is to a mass or energy source, the more paths through spacetime might be available to the…

High Energy Physics - Theory · Physics 2007-05-23 M. Dance

Magnitude homology is an invariant of enriched categories which generalizes ordinary categorical homology -- the homology of the classifying space of a small category. The classifying space can also be generalized in a different direction:…

Algebraic Topology · Mathematics 2025-03-27 Emily Roff

In this paper we define the magnitude of metric spaces using measures rather than finite subsets as had been done previously and show that this agrees with earlier work with Leinster in arXiv:0908.1582. An explicit formula for the magnitude…

Differential Geometry · Mathematics 2013-02-14 Simon Willerton

Magnitude is an isometric invariant of metric spaces introduced by Leinster. Although magnitude is nowhere continuous on the Gromov-Hausdorff space of finite metric spaces, continuity results are possible if we restrict the ambient space.…

Metric Geometry · Mathematics 2026-03-20 Sara Kalisnik , Davorin Lesnik

The magnitude of a graph is one of a family of cardinality-like invariants extending across mathematics; it is a cousin to Euler characteristic and geometric measure. Among its cardinality-like properties are multiplicativity with respect…

Combinatorics · Mathematics 2019-02-20 Tom Leinster

Magnitude homology of enriched categories, and in particular of metric spaces, was recently introduced by T. Leinster and M. Shulman. In this article, we prove that metric spaces satisfying a reasonably mild condition have vanishing…

Metric Geometry · Mathematics 2018-03-15 Benoit Jubin

The notion of the magnitude of a compact metric space was considered in arXiv:0908.1582 with Tom Leinster, where the magnitude was calculated for line segments, circles and Cantor sets. In this paper more evidence is presented for a…

Metric Geometry · Mathematics 2009-10-30 Simon Willerton

In spacetime physics, we frequently need to consider a set of all spaces (`universes') as a whole. In particular, the concept of `closeness' between spaces is essential. However, there has been no established mathematical theory so far…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Masafumi Seriu

We argue that the finiteness of quantum gravity amplitudes in fully compactified theories (at least in supersymmetric cases) leads to a bottom-up prediction for the existence of non-trivial dualities. In particular, finiteness requires the…

High Energy Physics - Theory · Physics 2025-08-20 Matilda Delgado , Damian van de Heisteeg , Sanjay Raman , Ethan Torres , Cumrun Vafa , Kai Xu

There is a general notion of the magnitude of an enriched category, defined subject to hypotheses. In topological and geometric contexts, magnitude is already known to be closely related to classical invariants such as Euler characteristic…

Rings and Algebras · Mathematics 2016-01-11 Joseph Chuang , Alastair King , Tom Leinster

The notion of the magnitude of a metric space was introduced by Leinster in [8] and developed in [10], [9], [11] and [16], but the magnitudes of familiar sets in Euclidean space are only understood in relatively few cases. In this paper we…

Metric Geometry · Mathematics 2016-07-14 Juan Antonio Barcelo , Anthony Carbery

Quantifying the distance between datasets is a fundamental question in mathematics and machine learning. We propose \textit{magnitude distance}, a novel distance metric defined on finite datasets using the notion of the \emph{magnitude} of…

Machine Learning · Computer Science 2026-02-10 Sahel Torkamani , Henry Gouk , Rik Sarkar

Metric magnitude is a measure of the "size" of point clouds with many desirable geometric properties. It has been adapted to various mathematical contexts and recent work suggests that it can enhance machine learning and optimization…

Machine Learning · Computer Science 2024-09-09 Rayna Andreeva , James Ward , Primoz Skraba , Jie Gao , Rik Sarkar

The Euler characteristic is an invariant of a topological space that in a precise sense captures its canonical notion of size, akin to the cardinality of a set. The Euler characteristic is closely related to the homology of a space, as it…

Algebraic Topology · Mathematics 2022-06-22 Nina Otter