Recently J. Zaks formulated the following Eberhard-type problem: Let (Ps, P6 .... ) be a finite sequence of nonnegative integers; does there exist a 5-valent 3-connected planar graph G such that it has exactly Pk k-gons for all k ~> 5, m i of its vertices meet exactly i triangles, 4 ~< i <~ 5, and m
Note on two problems of J. Zaks concerning Hamiltonian 3-polytopes
✍ Scribed by Hansjoachim Walther
- Publisher
- Elsevier Science
- Year
- 1981
- Tongue
- English
- Weight
- 313 KB
- Volume
- 33
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
✦ Synopsis
Let us denote by G(m, n) the family of all simple 3-poiytopes having ,just two types of faces, m-gons and n-gons. J. Z&s [3] proved that G(5; k) contains non-Hamiltonian members for all k, k 3 11, and asked among others the folfowing question: Do there exist non-Hamiltonian members in any of the families G(4; k) and G(3; k) for k 37?
.
We can prove the following ' .
Tborem I. G(4; k) contczim non-Hamhwtian members for akl odd k, k 3 9.
We will prove this theorem here only for k = 9, by constructing an appropriate graph 2 in G(4; 9). In a later paper we will show The~mm 2. The shortness exponent (see [l]) of the family G(4;k) is smaller than 1 for all odd k, k 3 17.
📜 SIMILAR VOLUMES
We present a solution of two problems of P. Erdijs on packing a set of r graphs into the complete graph on n vertices in such a way that each Hamiltonian cycle of the complete graph has common edges with each of the r packed graphs.