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In graph theory , one of the branches of mathematics , Berge's theorem is one of several theorems that go back to the French mathematician Claude Berge (1926–2002). Berge published the theorem in 1957 and thus gave a characterization of the largest possible matchings in finite graphs . In this publication, Berge also gave an algorithm for determining such a matching.

Formulation of the sentence

The sentence can be stated as follows:

A matching in a finite graph is of maximum power (and thus consists of exactly edges ) if and only if there is no -extending path .

Explanations

  • In a finite graph , a matching is of maximum power if and only if there is no other matching with . The power of such a largest possible matching is called the matching number of and denotes it with .
  • Is a path in given, is as -alternierend designated if in to alternately occurring edges to and include.
  • Incising by a -alternierenden path associated with none of the end node in occurring edges, it is as -erweiternd (or as -zunehmend hereinafter).

Remarks

  • In the English-language graph theory literature one speaks of an augmenting path. This is why Berge's theorem is also known here as the augmenting path theorem .
  • The sentence already appears in the pioneering work The Theory of Regular Graphs by the Danish mathematician Julius Petersen from 1891.
  • Often (as in the Bronstein, for example ) a matching of maximum power is also briefly called a maximum matching , although this designation does not correspond to the otherwise usual concept of maximality, which comes from order theory .

Web links

literature

Individual evidence

  1. Claude Berge: Graphs and Hypergraphs. 1973, p. 124.
  2. John Clark, Derek Allan Holton: Graph Theory. 1994, p. 137.
  3. ^ Lutz Volkmann: Foundations of the graph theory. 1996, p. 117.
  4. ^ A b I. N. Bronstein, KA Semendjajev and others: Pocket book of mathematics. 2016, p. 420.
  5. ^ Dieter Jungnickel: Graphs, Networks and Algorithms. 2008, p. 390 ff.
  6. a b Jonathan L. Gross, Jay Yellen (Ed.): Handbook of Graph Theory. 2004, p. 1105.