{ "id": "1809.07866", "version": "v1", "published": "2018-09-20T21:11:57.000Z", "updated": "2018-09-20T21:11:57.000Z", "title": "Constructions and uses of incomplete pairwise balanced designs", "authors": [ "Peter J. Dukes", "Esther R. Lamken" ], "categories": [ "math.CO" ], "abstract": "We give explicit constructions for incomplete pairwise balanced designs IPBD$((v;w),K)$, or, equivalently, edge-decompositions of a difference of two cliques $K_v \\setminus K_w$ into cliques whose sizes belong to the set $K$. Our constructions produce such designs whenever $v$ and $w$ satisfy the usual divisibility conditions, have ratio $v/w$ bounded away from the smallest value in $K$ minus one, say $v/w > k-1+\\epsilon$, for $k =\\min K$ and $\\epsilon>0$, and are sufficiently large (depending on $K$ and $\\epsilon$). As a consequence, some new results are obtained on many related designs, including class-uniformly resolvable designs, incomplete mutually orthogonal latin squares, and group divisible designs. We also include several other applications that illustrate the power of using IPBDs as `templates'.", "revisions": [ { "version": "v1", "updated": "2018-09-20T21:11:57.000Z" } ], "analyses": { "subjects": [ "05B05", "05B15", "05C70" ], "keywords": [ "constructions", "incomplete mutually orthogonal latin squares", "usual divisibility conditions", "incomplete pairwise balanced designs ipbd", "sizes belong" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }