Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-26T18:58:10.118Z Has data issue: false hasContentIssue false

Set Families With a Forbidden Induced Subposet

Published online by Cambridge University Press:  22 March 2012

EDWARD BOEHNLEIN
Affiliation:
Department of Mathematics, Miami University, Oxford, OH 45056, USA (e-mail: [email protected], [email protected])
TAO JIANG
Affiliation:
Department of Mathematics, Miami University, Oxford, OH 45056, USA (e-mail: [email protected], [email protected])

Abstract

For each poset H whose Hasse diagram is a tree of height k, we show that the largest size of a family of subsets of [n]={1,. . ., n} not containing H as an induced subposet is asymptotic to . This extends a result of Bukh [1], which in turn generalizes several known results including Sperner's theorem.

Type
Paper
Copyright
Copyright © Cambridge University Press 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1]Bukh, B. (2009) Set families with a forbidden subposet. Electron. J. Combin. 16 #R142.CrossRefGoogle Scholar
[2]Carroll, T. and Katona, G. O. H. (2008) Bounds on maximal families of sets not containing three sets with ABC, A∉⊂B. Order 25 229236.CrossRefGoogle Scholar
[3]De Bonis, A. and Katona, G. O. H. (2007) Largest families without an r-fork. Order 24 181191.CrossRefGoogle Scholar
[4]De Bonis, A., Katona, G. O. H. and Swanepoel, K. J. (2005) Largest families without ABCD. J. Combin. Theory Ser. A 111 331336.CrossRefGoogle Scholar
[5]Erdős, P. (1945) On a lemma of Littlewood and Offord. Bull. Amer. Math. Soc. 51 898902.CrossRefGoogle Scholar
[6]Griggs, J. and Lu, L. (2009) On families of subsets with a forbidden subposet. Combin. Probab. Comput. 18 731748.CrossRefGoogle Scholar
[7]Sperner, E. (1928) Ein Satz über Untermengen einer endlichen Menge. Math. Z. 27 544548.CrossRefGoogle Scholar
[8]Thanh, H. T. (1998) An extremal problem with excluded subposets in the Boolean lattice. Order 15 5157.CrossRefGoogle Scholar