Heawood conjecture
id:
heawood-conjecture-166-7760563
title:
Heawood conjecture
text:
In graph theory, the Heawood conjecture or Ringel–Youngs theorem gives a lower bound for the number of colors that are necessary for graph coloring on a surface of a given genus. For surfaces of genus 0, 1, 2, 3, 4, 5, 6, 7,..., the required number of colors is 4, 7, 8, 9, 10, 11, 12, 12,.... OEIS: A000934, the chromatic number or Heawood number. The conjecture was formulated in 1890 by P.J. Heawood and proven in 1968 by Gerhard Ringel and J.W.T. Youngs. One case, the non-orientable Klein bottle
brand slug:
wiki
category slug:
encyclopedia
description:
Theorem on graph coloring on surfaces
original url:
https://en.wikipedia.org/wiki/Heawood_conjecture
date created:
2005-03-09T04:40:46Z
date modified:
2024-08-29T21:23:38Z
main entity:
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image:
{"content_url":"https://upload.wikimedia.org/wikipedia/commons/d/de/7_colour_torus.svg","width":512,"height":512}
fields total:
13
integrity:
16