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: Tuesday, March 27, 2007, 12:15 pm

Duration: This information is not available in the database

Location: CAB G51

Speaker: Leo Rüst

The Hidden-K-Matrix Linear Complementarity Problem

Given a square matrix M and a vector q, the Linear Complementarity Problem (LCP) is to find nonnegative vectors w and z such that w-Mz=q and in every component either w or z is zero. The LCP has a unique solution for every q if and only if M is a P-matrix, a matrix whose principal minors are all positive. Hardness of the P-matrix LCP would imply that NP is equal to coNP, which is very unlikely. On the other hand, there is no polynomial time algorithm known.

In this talk we restrict our focus to the class of hidden-K-matrices, an interesting and nontrivial subclass of P-matrices known to be solvable in polynomial time. Up to now, hidden-K-matrices have been looked at only from an algebraic point of view. We shed some light onto the combinatorial structure of the hidden-K-matrix LCP, in particular we show that the orientation implicitly underlying a hidden-K-matrix LCP is acyclic for every q.

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