Department of Computer Science | Institute of Theoretical Computer Science | CADMO

Prof. Emo Welzl and Prof. Bernd Gärtner

Mittagsseminar Talk Information |

**Date and Time**: Tuesday, March 28, 2023, 12:15 pm

**Duration**: 30 minutes

**Location**: OAT S15/S16/S17

**Speaker**: Martin Fürer (Pennsylvania State University)

Most NP-hard graph problems can be solved efficiently when restricted to graphs of small width and provided with a corresponding tree decomposition. Thus, it is essential to find good tree decompositions efficiently. The goal is to approximate the width by a small constant factor and to have an efficient FPT (fixed parameter tractable) algorithm. FPT means that the time is O(f(k)g(n)) where k is the parameter (in this case the treewidth), n is the size of the input, f is a computable function and g is bounded by a polynomial. Korhonen’s [2021] new algorithm achieves a ratio of 2 with g linear. However, f remains a stumbling block for fast algorithms. Tree Decomposition (of width at most k) is NP-complete. Therefore, f(k) = O*(c^{k}), achieved by several algorithms, is theoretically satisfactory, but the base c is large. (O* omits polynomial factors.) This talk is about decreasing c. It starts with a quick review of the classical O*(4^{3k}) n^{2} algorithm of Robertson and Seymour [1995] and the 2^{O(k log k)} n log n improvement by Reed [1992]. Joint work with Mahdi Belbasi.

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