Abstract
A Steiner triple system of order v, or STS(v), is a pair (V, ) with V a set of v points and
a set of 3-subsets of V called blocks or triples, such that every pair of distinct elements of V occurs in exactly one triple. The intersection problem for STS is to determine the possible numbers of blocks common to two Steiner triple systems STS(u), (U,
), and STS(v), (V,
), with U⊆V. The case where U=V was solved by Lindner and Rosa in 1975. Here, we let U⊂V and completely solve this question for v−u=2,4 and for v≥2u−3.
Similar content being viewed by others
References
Darryn Bryant and Daniel Horsley, A proof of Lindner's conjecture on embeddings of partial Steiner triple systems, preprint
Butler, R.A.R., Hoffman, D.G.: Intersections of group divisible triple systems, Ars. Combin. 34, 268–288 (1992)
Colbourn, C.J., Dinitz, J.H. eds.: The CRC Handbook of Combinatorial Designs. CRC Press, Boca Raton, (1996)
Colbourn, C.J., Rosa, A.: Triple Systems, Oxford Science Publications, Clarendon Press (1999)
Danziger, P., Dukes, P., Griggs, T.S., Mendelsohn, E.: On the intersection problem for Steiner triple systems of different orders, University of Toronto Department of Computer Science Technical Report #DCS 322/06 2006. http://www.math.utoronto.ca/mendelso/pub/techreport_intersections.pdf
Doyen J., Wilson, R.M.: Embeddings of Steiner triple systems. Discrete Math. 5, 229–239 (1973)
Dukes, P.: Disjoint partial triple systems of different orders, Ars. Combin., to appear
Dukes, P., Mendelsohn, E.: Quasi-embeddings of Steiner triple systems, or Steiner triple systems of different orders having maximum intersection. J. Combin. Des. 13, 120–138 (2005)
Grannell, M.J., Griggs, T.S., Mendelsohn, E.: A small basis for four-line configurations in Steiner triple systems. J. Combin. Des. 3, 51–59 (1995)
Lindner, C.C., Rosa, A.: Steiner triple systems having a prescribed number of triples in common. Canad. J. Math. 27, 1166–1175 (1975)
Stern, G., Lenz, H.: Steiner triple systems with given subspaces; another proof of the Doyen-Wilson theorem. Boll. Un. Mat. Ital. A (5) 17, 109–114 (1980)
Author information
Authors and Affiliations
Corresponding author
Additional information
supported by NSERC research grant #OGP0170220.
supported by NSERC postdoctoral fellowship.
supported by NSERC research grant #OGP007621.
About this article
Cite this article
Danziger, P., Dukes, P., Griggs, T. et al. On the Intersection Problem for Steiner Triple Systems of Different Orders. Graphs and Combinatorics 22, 311–329 (2006). https://doi.org/10.1007/s00373-006-0664-1
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s00373-006-0664-1