Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4647382 | Discrete Mathematics | 2013 | 9 Pages |
Abstract
Let (X,B) be a simple twofold triple system of order v. For every x,yâX, xâ y, the pair {x,y} is contained in exactly two different triples, say, {x,y,z} and {x,y,w}. Any two blocks B1,B2âB satisfying |B1â©B2|=2 form a matched pair. Suppose that there is a partition of B into |B|/2 matched pairs. If we replace the double edge {x,y} with its corresponding single edge {x,y} from a matched pair {x,y,z}, {x,y,w}, we have a (K4âe)[x,y,zâw]. Let C be the collection of (K4âe)s obtained by replacing the double edge of each matched pair of B with its corresponding single edge, and F be the collection of the deleted edges. If F can be reassembled into a collection D of âv(vâ1)/30â(K4âe)s, then (X,CâªD) is a maximum twofold (K4âe)-packing of order v. We call (X,CâªD) a metamorphosis of the simple twofold triple system (X,B). In this paper, we show that there exists a metamorphosis of a simple twofold triple system of order v into a maximum twofold (K4âe)-packing of order v if and only if vâ¡0,1(mod3) and vâ¥4 with two exceptions of v=6,7 and one possible exception of v=18.
Keywords
Related Topics
Physical Sciences and Engineering
Mathematics
Discrete Mathematics and Combinatorics
Authors
Yanxun Chang, Tao Feng, Giovanni Lo Faro, Antoinette Tripodi,