Undirected unit-distance graph requiring four colors
Moser spindle
Named after
Leo Moser, William Moser
Vertices
7
Edges
11
Radius
2
Diameter
2
Girth
3
Automorphisms
8
Chromatic number
4
Chromatic index
4
Properties
planar unit distance Laman graph
Table of graphs and parameters
In graph theory, a branch of mathematics, the Moser spindle (also called the Mosers' spindle or Moser graph) is an undirected graph, named after mathematicians Leo Moser and his brother William,[1] with seven vertices and eleven edges. It is a unit distance graph requiring four colors in any graph coloring, and its existence can be used to prove that the chromatic number of the plane is at least four.[2]
The Moser spindle has also been called the Hajós graph after György Hajós, as it can be viewed as an instance of the Hajós construction.[3] However, the name "Hajós graph" has also been applied to a different graph, in the form of a triangle inscribed within a hexagon.[4]
^Moser, L.; Moser, W. (1961), "Solution to problem 10", Can. Math. Bull., 4: 187–189, doi:10.1017/S0008439500025753, S2CID 246244722.
^Soifer, Alexander (2008), The Mathematical Coloring Book: Mathematics of Coloring and the Colorful Life of its Creators, New York: Springer, pp. 14–15, ISBN 978-0-387-74640-1.
^Bondy, J. A.; Murty, U. S. R. (2008), Graph Theory, Graduate Texts in Mathematics, vol. 244, Springer, p. 358, doi:10.1007/978-1-84628-970-5, ISBN 978-1-84628-969-9.
^Berge, C. (1989), "Minimax relations for the partial q-colorings of a graph", Discrete Mathematics, 74 (1–2): 3–14, doi:10.1016/0012-365X(89)90193-3, MR 0989117.
mathematics, the Moserspindle (also called the Mosers' spindle or Moser graph) is an undirected graph, named after mathematicians Leo Moser and his brother...
Moser polygon notation, a means of expressing certain extremely large numbers Moserspindle, an undirected graph named after mathematicians Leo Moser...
Leo Moser (11 April 1921, Vienna – 9 February 1970, Edmonton) was an Austrian-Canadian mathematician, best known for his polygon notation. A native of...
requires four colors in any graph coloring. Thus, like the simpler Moserspindle, it provides a lower bound for the Hadwiger–Nelson problem: coloring...
W_{7}} (the only wheel graph that is a unit distance graph), and the Moserspindle and Golomb graph (small 4-chromatic unit distance graphs). All generalized...
attained under a more complicated graph where multiple four-coloring Moserspindles are linked so that no monochromatic triples exist in any coloring of...
indicates that the stem is spindle-shaped (from the Latin fusus meaning "spindle" and pes meaning "foot"). The English name "Spindle Shank" has been given...
for television in-name only). Terrytoons was founded by Paul Terry, Frank Moser, and Joseph Coffman, and operated out of the "K" Building in downtown New...
(5th ed.). Sunderland, Mass.: Sinauer. p. 590. ISBN 978-0878936953. Moser MB, Moser EI (1998). "Functional differentiation in the hippocampus". Hippocampus...
La Cava; animated by Frank Moser and Raoul Barré Krazy Kat (1916-1917): directed by Gregory La Cava; animated by Frank Moser, Leon Searl, Bill Nolan, Bert...
(1914–1968), Oberst in the Fallschirmjäger during World War II Wilhelm Spindler (1914–1997), Oberst in the Wehrmacht during World War II Rudolf von Bünau...