STEINER TRIPLE-SYSTEMS;
OBERWOLFACH-PROBLEM;
COMPLETE GRAPH;
LATIN SQUARES;
FACTORIZATIONS;
DECOMPOSITIONS;
D O I:
10.1016/j.ejc.2016.07.001
中图分类号:
O1 [数学];
学科分类号:
0701 ;
070101 ;
摘要:
A 2t-cycle system of even order v is a set C of cycles of length 2t whose edges partition the edge-set of K-v - I (i.e., the complete graph minus the 1-factor I). If v equivalent to 0 (mod 2t), a set of v/2t vertex disjoint cycles of C is a parallel class. If C has no parallel classes, we call such a system unparalleled. We show that there exists an unparalleled 2t-cycle system of order v equivalent to 0 (mod 2t) if and only if v > 2t > 2. (C) 2016 Elsevier Ltd. All rights reserved.