Hypergraphs | Graph theory

Vertex cover in hypergraphs

In graph theory, a vertex cover in a hypergraph is a set of vertices, such that every hyperedge of the hypergraph contains at least one vertex of that set. It is an extension of the notion of vertex cover in a graph. An equivalent term is a hitting set: given a collection of sets, a set which intersects all sets in the collection in at least one element is called a hitting set. The equivalence can be seen by mapping the sets in the collection onto hyperedges. Another equivalent term, used more in a combinatorial context, is transversal. The notions of hitting set and set cover are equivalent too. (Wikipedia).

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Vertex Covers and Vertex Covering Numbers | Graph Theory

We introduce vertex covers, minimum vertex covers, and vertex covering numbers! We'll see some examples and non-examples of vertex covers, as well as minimum vertex covers and some that aren't minimum. The number of vertices in a minimum vertex cover is called the vertex covering number of

From playlist Graph Theory

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Complement of Independent Set is Vertex Cover | Graph Theory

We prove the complement of an independent vertex set is a vertex cover. This makes for an easy direct proof once we recall our definitions. An independent vertex set is a set of vertices, no two of which are adjacent. A vertex cover is a set of vertices such that every edge has at least on

From playlist Graph Theory

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Raffaella Mulas - Spectral theory of hypergraphs

Hypergraphs are a generalization of graphs in which vertices are joined by edges of any size. In this talk, we generalize the graph normalized Laplace operators to the case of hypergraphs, and we discuss some properties of their spectra. We discuss the geometrical meaning of the largest an

From playlist Research Spotlight

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Vertex Covering Number of Complete Graphs | Graph Theory Exercises

We discuss and prove the vertex covering number of a complete graph Kn is n-1. That is, the minimum number of vertices needed to cover a complete graph is one less than its number of vertices. This is because, put simply, if we are missing at least 2 vertices in our attempted vertex cover,

From playlist Graph Theory Exercises

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Emilie Purvine (5/2/21): Homology of Graphs and Hypergraphs

Graphs and hypergraphs are typically studied from a combinatorial perspective. A graph being a collection of vertices and pairwise relationships (edges) among the vertices, and a hypergraph capturing multi-way or groupwise relationships (hyperedges) among the vertices. But both of these ob

From playlist TDA: Tutte Institute & Western University - 2021

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Parabolas 11 Algebra Regents

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From playlist Parabolas

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Quadric Surface: The Hyperbolic Paraboloid

This video explains how to determine the traces of a hyperbolic paraboloid and how to graph a hyperbolic paraboloid. http://mathispower4u.yolasite.com/

From playlist Quadric, Surfaces, Cylindrical Coordinates and Spherical Coordinates

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Complement of Vertex Cover is Independent Vertex Set | Graph Theory

We prove the complement of a vertex cover is an independent vertex set. Recall a vertex cover is a set of vertices covering all edges of the graph, meaning every edge has at least one end vertex in the cover. As a result, the complement of a cover cannot possible have two vertices joined b

From playlist Graph Theory

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Hyperbola 3D Animation | Objective conic hyperbola | Digital Learning

Hyperbola 3D Animation In mathematics, a hyperbola is a type of smooth curve lying in a plane, defined by its geometric properties or by equations for which it is the solution set. A hyperbola has two pieces, called connected components or branches, that are mirror images of each other an

From playlist Maths Topics

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Hypergraph matchings and designs – Peter Keevash – ICM2018

Combinatorics Invited Lecture 13.10 Hypergraph matchings and designs Peter Keevash Abstract: We survey some aspects of the perfect matching problem in hypergraphs, with particular emphasis on structural characterisation of the existence problem in dense hypergraphs and the existence of d

From playlist Combinatorics

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DSI | Hypergraphs and Topology for Data Science | By Emilie Purvine

Data scientists and applied mathematicians must grapple with complex data when analyzing complex systems. Analytical methods almost always represent phenomena as a much simpler level than the complex structure or dynamics inherent in systems, through either simpler measured or sampled data

From playlist DSI Virtual Seminar Series

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Rainbow Matchings in Hypergraphs - Cosmin Pohoata

Computer Science/Discrete Mathematics Seminar II Topic: Rainbow Matchings in Hypergraphs Speaker: Cosmin Pohoata Affiliation: IAS - Member, School of Mathematics Date: February 14, 2023 Suppose we are given matchings M1,....,MN of size t in some r-uniform hypergraph, and let us think of

From playlist Mathematics

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The Hypergraph Container Method, Partition Containers, and Algorithmic Applications - Or Zamir

Computer Science/Discrete Mathematics Seminar II Topic: The Hypergraph Container Method, Partition Containers, and Algorithmic Applications Speaker: Or Zamir Affiliation: Visitor, School of Mathematics Date: November 29, 2022  The recently-discoverd Hypergraph Container Method (Saxton an

From playlist Mathematics

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More designs - P. Keevash - Workshop 1 - CEB T1 2018

Peter Keevash (Oxford) / 01.02.2018 We generalise the existence of combinatorial designs to the setting of subset sums in lattices with coordinates indexed by labelled faces of simplicial complexes. This general framework includes the problem of decomposing hypergraphs with extra edge dat

From playlist 2018 - T1 - Model Theory, Combinatorics and Valued fields

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Chandra Chekuri: On element connectivity preserving graph simplification

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From playlist HIM Lectures 2015

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Wolfram Physics I: Basic Formalism, Causal Invariance and Special Relativity

Find more information about the summer school here: https://education.wolfram.com/summer/school Stay up-to-date on this project by visiting our website: http://wolfr.am/physics Check out the announcement post: http://wolfr.am/physics-announcement Find the tools to build a universe: https:

From playlist Wolfram Summer Programs

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The method of hypergraph containers – József Balogh & Robert Morris – ICM2018

Combinatorics Invited Lecture 13.6 The method of hypergraph containers József Balogh & Robert Morris Abstract: In this survey we describe a recently-developed technique for bounding the number (and controlling the typical structure) of finite objects with forbidden substructures. This te

From playlist Combinatorics

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Finding the Equation of the Parabola Given a Point and the Vertex

Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys Finding the Equation of the Parabola Given a Point and the Vertex. We are also told which way the parabola opens.

From playlist Parabolas

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Combinatorial optimization | Matching in hypergraphs | Intersection (set theory) | K-approximation of k-hitting set | Map (mathematics) | Fano plane | Combinatorics | Game theory | Empty set | Set cover problem | Graph theory | Bipartite graph | Vertex (graph theory) | Unique games conjecture | Boolean satisfiability problem | Race condition | Hypergraph | Prime power | Matching (graph theory) | Data mining