A Steiner triple system of order n (STS(n)) is said to be embeddable in an orientable surface if there is an orientable embedding of the complete graph Kn whose faces can be properly 2-colored (say, black and white) in such a way that all black faces are triangles and these are precisely the blocks
Embeddings of Steiner triple systems
β Scribed by Jean Doyen; Richard M. Wilson
- Publisher
- Elsevier Science
- Year
- 1973
- Tongue
- English
- Weight
- 867 KB
- Volume
- 5
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
β¦ Synopsis
If X is a set whose elements are called points and A is a collectioxr of subsets of X (called lines) such that:
(i) any two distinct points of X are contained in exactly one line, (ii) every line contains at least two points, we say that the pair (X, A) is a linear space.
A Steiner triple system is defilaed as a finite nocempty linear space (X, A) all of whose lines are of size 3, i.e., contain exactly 3 points. A Steiner triple system with 1x1 = u is said to be of order u and is denoted by S(u). Kirkman [ 41 has proved that th.ere exist. 4 an S(u) if and only if u 2 1 or 3 (mod 6); any positive integer satisfying this congruence will be called admissible.
If (X, A) and (Y, 23) are two Steiner triple systc':ms such that Y E X and B c A, we :;hall say that (Y, B) is embedded in (or is a subsystem of) (X, A) and that (X, A) contains (Y, 8). If (X, A) is) of order u and (Y, 8) is of order u < u, then u > 2u + 1. Indeed, let p E X -Y. Any line cow taining p has aa: most one point in Y. Therefore tlhere are exactly er lines
π SIMILAR VOLUMES
## Abstract In this paper, we present a conjecture that is a common generalization of the DoyenβWilson Theorem and Lindner and Rosa's intersection theorem for Steiner triple systems. Given __u__, __v__ β‘ 1,3 (mod 6), __u__ < __v__ < 2__u__β+β 1, we ask for the minimum __r__ such that there exists a
## Abstract A cyclic face 2βcolourable triangulation of the complete graph __K__~__n__~ in an orientable surface exists for __n__ββ‘β7 (mod 12). Such a triangulation corresponds to a cyclic biβembedding of a pair of Steiner triple systems of order __n__, the triples being defined by the faces in eac
## Abstract A wellβknown, and unresolved, conjecture states that every partial Steiner triple system of order __u__ can be embedded in a Steiner triple system of order Ο for all Ο ββ‘ 1 or 3, (mod 6), Ο ββ₯β2uβ+β1. However, some partial Steiner triple systems of order __u__ can be embedded in Steiner t
## Abstract Lindner's conjecture that any partial Steiner triple system of order __u__ can be embedded in a Steiner triple system of order __v__ if $v\equiv 1,3 \; ({\rm mod}\; 6)$ and $v\geq 2u+1$ is proved. Β© 2008 Wiley Periodicals, Inc. J Combin Designs 17: 63β89, 2009