Department of Computer Science | Institute of Theoretical Computer Science | CADMO

Theory of Combinatorial Algorithms

Prof. Emo Welzl and Prof. Bernd Gärtner

Mittagsseminar (in cooperation with M. Ghaffari, A. Steger and B. Sudakov)

Mittagsseminar Talk Information

Date and Time: Tuesday, September 28, 2010, 12:15 pm

Duration: This information is not available in the database

Location: CAB G51

Speaker: Heidi Gebauer

Constructing a Non-Two-Colorable Hypergraph with Few Edges

We say that a given k-uniform hypergraph is non-two-colorable if every red/blue-coloring of its vertices yields an edge where all vertices have the same color. It is a long-standing open problem to determine the minimum number m(k) such that there exists a non-2-colorable k-uniform hypergraph with m(k) hyperedges. Erdos showed, using the probabilistic method, that m(k) <= O(k^2 * 2^k), and by a result of Radhakrishnan and Srinivasan, m(k) >= \Omega(\sqrt(k/ln k) 2^k). These are the best known bounds. This talk will be about an explicit construction of a non-two-colorable hypergraph with 2^(k(1+o(1)) edges.

Upcoming talks     |     All previous talks     |     Talks by speaker     |     Upcoming talks in iCal format (beta version!)

Previous talks by year:   2018  2017  2016  2015  2014  2013  2012  2011  2010  2009  2008  2007  2006  2005  2004  2003  2002  2001  2000  1999  1998  1997  1996  

Information for students and suggested topics for student talks

Automatic MiSe System Software Version 1.4803M   |   admin login