In the mathematical field of graph theory, the Dürer graph is an undirected graph with 12 vertices and 18 edges. It is named after Albrecht Dürer, whose 1514 engraving Melencolia I includes a depiction of Dürer's solid, a convex polyhedron having the Dürer graph as its skeleton. Dürer's solid is one of only four well-covered simple convex polyhedra.
Dürer's solid is combinatorially equivalent to a cube with two opposite vertices truncated, although Dürer's depiction of it is not in this form but rather as a truncated rhombohedron or triangular truncated trapezohedron. The exact geometry of the solid depicted by Dürer is a subject of some academic debate, with different hypothetical values for its acute angles ranging from 72° to 82°.
The Dürer graph
|Named after||Albrecht Dürer|
|Table of graphs and parameters|
The Dürer graph is the graph formed by the vertices and edges of the Dürer solid. It is a cubic graph of girth 3 and diameter 4. As well as its construction as the skeleton of Dürer's solid, it can be obtained by applying a Y-Δ transform to the opposite vertices of a cube graph, or as the generalized Petersen graph G(6,2). As with any graph of a convex polyhedron, the Dürer graph is a 3-vertex-connected simple planar graph.
The Dürer graph is a well-covered graph, meaning that all of its maximal independent sets have the same number of vertices, four. It is one of four well-covered cubic polyhedral graphs and one of seven well-covered 3-connected cubic graphs. The only other three well-covered simple convex polyhedra are the tetrahedron, triangular prism, and pentagonal prism.
The Dürer graph is Hamiltonian, with LCF notation [-4,5,2,-4,-2,5;-]. More precisely, it has exactly six Hamiltonian cycles, each pair of which may be mapped into each other by a symmetry of the graph.
The Dürer graph is Hamiltonian.
|Wikimedia Commons has media related to Dürer graph.|
- Weisstein, Eric W. "Dürer's Solid". MathWorld.
- Weber (1900).
- Weitzel (2004).
- Campbell & Plummer (1988); Campbell, Ellingham & Royle (1993).
- Castagna & Prins (1972) attribute the proof of Hamiltonicity of a class of generalized Petersen graphs that includes the Dürer graph to a 1968 Ph.D. thesis of G. N. Robertson at the University of Waterloo.
- Schwenk (1989).
- Campbell, S. R.; Ellingham, M. N.; Royle, Gordon F. (1993), "A characterisation of well-covered cubic graphs", Journal of Combinatorial Mathematics and Combinatorial Computing, 13: 193–212, MR 1220613.
- Campbell, Stephen R.; Plummer, Michael D. (1988), "On well-covered 3-polytopes", Ars Combinatoria, 25 (A): 215–242, MR 0942505.
- Castagna, Frank; Prins, Geert (1972), "Every Generalized Petersen Graph has a Tait Coloring", Pacific Journal of Mathematics, 40, doi:10.2140/pjm.1972.40.53.
- Schwenk, Allen J. (1989), "Enumeration of Hamiltonian cycles in certain generalized Petersen graphs", Journal of Combinatorial Theory, Series B, 47 (1): 53–59, doi:10.1016/0095-8956(89)90064-6, MR 1007713.
- Weber, P. (1900), Beiträge zu Dürers Weltanschauung—Eine Studie über die drei Stiche Ritter, Tod und Teufel, Melancholie und Hieronymus im Gehäus, Strassburg. As cited by Weitzel (2004).
- Weitzel, Hans (2004), "A further hypothesis on the polyhedron of A. Dürer's engraving Melencolia I", Historia Mathematica, 31 (1): 11–14, doi:10.1016/S0315-0860(03)00029-6.