Department of Computer Science | Institute of Theoretical Computer Science | CADMO
Prof. Emo Welzl and Prof. Bernd Gärtner
|Mittagsseminar Talk Information|
Date and Time: Tuesday, February 20, 2007, 12:15 pm
Duration: This information is not available in the database
Location: CAB G51
Speaker: Florian Zickfeld (TU Berlin)
Orientations of planar maps (that is planar graphs with fixed embeddings) with out-degrees given by a function α are called α-orientations. The concept of an α-orientation provides a unified approach to many structures such as Eulerian orientations, bipartite f-factors, Schnyder woods and bipolar orientations. For a given class of planar maps and out-degree functions we study the maximum number of α-orientations that can occur.
I explain how the number of α-orientations on a planar map with n vertices can be bounded from above by 3.73^n and introduce a family of plane graphs with 2.598^n α-orientations. I also present specialized bounds for the above mentioned structures. I then discuss a reduction to counting bipartite perfect matchings and known facts about the complexity of counting α-orientations. I conclude by posing some open problems.
Joint work with Stefan Felsner.
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