# Noon lecture

list of noon lectures ( 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | future lectures)

On 21.09.2007 at 12:10 in S6, there is the following noon lecture:

# Large families of subsets avoiding a given configuration

## Jerrold R. Griggs

## University of South Carolina, Columbia, SC

## Abstract

Translating Tur\'an-type questions to ordered sets, we are interested in the maximum size La(n,H) of a family F of subsets of the set {1,2,...,n}, subject to the condition that a certain configuration (subposet H) is excluded.

For instance, Sperner's Theorem solves the problem for H being a two-element chain. We survey results of this kind, including bounds when H is the four-element N poset (joint with Gyula O.H. Katona) or a more general height two poset (joint with Linyuan Lincoln Lu).

list of noon lectures ( 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | future lectures)

Webmaster: kamweb.mff.cuni.cz Modified: 19. 10. 2010