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: Thursday, October 05, 2017, 12:15 pm

Duration: 30 minutes

Location: CAB G51

Speaker: Dániel Korándi (EPFL)

On the Turán number of ordered forests

An ordered graph $H$ is a graph with a linear ordering on its vertex set. The corresponding Turán problem, first studied by Pach and Tardos, asks for the maximum number $\ex_ n^{1+\eps}$ for some positive $\eps=\eps(H)$ unless $H$ is a forest that has a bipartition $V_1\cup V_2$ such that $V_1$ totally precedes $V_2$ in the ordering. Making progress towards a conjecture of Pach and Tardos, we prove that $\ex_{\le}(n,H) =n^{1+o(1)}$ holds for all such forests that are "degenerate" in a certain sense. This class includes every forest for which an $n^{1+o(1)}$ upper bound was previously known, as well as new examples. For example, the class contains all forests with $|V_1|\le 3$. Our proof is based on a density-increment argument. Joint work with Gábor Tardos, István Tomon and Craig Weidert


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

Previous talks by year:   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