Mittagsseminar (in cooperation with J. Lengler, A. Steger, and D. Steurer)

Date and Time: Tuesday, November 20, 2007, 12:15 pm

Duration: This information is not available in the database

Location: OAT S15/S16/S17

Speaker: Dan Hefetz

Antimagic graphs via the Combinatorial Nullstellensatz

An antimagic labeling of a graph with n vertices and m edges is a bijection from the set of edges to the integers 1,...,m such that all n vertex sums are pairwise distinct, where a vertex sum is the sum of labels of all edges incident with that vertex. A graph is called antimagic if it admits an antimagic labeling. In 1990, it was conjectured by Ringel that any simple connected graph, other than K_2, is antimagic. Despite some efforts (and some partial results) in recent years, this conjecture is still open. In this talk I will sketch a proof of one partial result; namely, any graph on n = 3^k vertices which admits a triangle factor is antimagic. The main tool that will be used is a powerful algebraic method called the Combinatorial Nullstellensatz.

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

Previous talks by year:   2024  2023  2022  2021  2020  2019  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