Mittagsseminar (in cooperation with A. Steger, D. Steurer and B. Sudakov)

Date and Time: Thursday, April 24, 2008, 12:15 pm

Duration: This information is not available in the database

Location: OAT S15/S16/S17

Speaker: Torsten Mütze

Antimagic Labellings of Graphs

An antimagic labelling of an undirected graph G=(V,E) is a bijective mapping from E to {1,2,...,|E|} such that all vertex sums are distinct, where a vertex sum is the sum of the labels of all edges incident with that vertex. A graph is called antimagic if it has an antimagic labelling. A conjecture of Ringel and Hartsfield from 1990 states that all connected graphs but K_2 are antimagic. In this talk we discuss antimagic labellings of directed graphs (here vertex sums are signed, counting labels of incoming edges positively and labels of outgoing edges negatively). There exists a variety of methods to prove antimagicness for certain graphs, from algorithmic to algebraic techniques (Combinatorial Nullstellensatz) and probabilistic methods (Lovász Local Lemma). We will put particular emphasis on these different techniques and highlight the relations between the directed and the undirected case.

Joint work with Dan Hefetz and Justus Schwartz.

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

Previous talks by year:   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