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, May 07, 2009, 12:15 pm

Duration: This information is not available in the database

Location: CAB G51

Speaker: Andrea Francke

The Euclidean Degree-4 Minimum Spanning Tree Problem is NP-hard

The Euclidean degree-k minimum spanning tree (E-Dk-MST) problems are defined as follows: Given a set P of n points in the plane and a positive integer w, is there a spanning tree of the points in P with no vertex degree exceeding k that has weight <= w?

The complexity of the E-Dk-MST problems has long been known for all k except k=4. In particular, the E-D2-MST problem corresponds to the path-version of the traveling salesman problem and is NP-complete. The E-D3-MST problem is NP-complete, too, while for k >= 5, the E-Dk-MST problem is solvable in polynomial time. The remaining case, i.e. the E-D4-MST problem, was conjectured to be NP-hard by Papadimitriou and Vazirani in 1984.

In the talk, I will present a proof of the conjecture based on a reduction from vertex cover in cubic planar graphs.

Joint work with Michael Hoffmann.

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