On generalized Kneser hypergraph colorings

In Ziegler (2002), the second author presented a lower bound for the chromatic numbers of hypergraphs KGr sssS, “generalized r-uniform Kneser hypergraphs with intersection multiplicities sss.” It generalized previous lower bounds by Kˇr´ıˇz (1992/2000) for the case sss = (1, . . . , 1) without intersection multiplicities, and by Sarkaria (1990) for S = [n] k . Here we discuss subtleties and difficulties that arise for intersection multiplicities si > 1:

• Type: Journal
• Year: 2007
• Where: JCT
• Authors: Carsten E. M. C. Lange, Günter M. Ziegler
• Keywords: Hypergraphs Kgr SssS, Intersection Multiplicities, JCT 2007, Lower Bounds