Seminar on Foundations of Computing
This research seminar provides a venue for presenting research results concerning algorithm design, discrete mathematics, formal methods, logic and related areas of theoretical computer science. The seminar is jointly organized by the research laboratories DIMEA, FORMELA, and LIVE. The seminar builds on the FMDSA seminar organized by the FORMELA laboratory in the past.
Time and place
The seminar takes place on Monday at 2PM term time in Room C417 in the building of the Faculty of Informatics on a (roughly) weekly schedule.
Spring 2024 – schedule overview
February 19 | Liana Khazaliya (TU Vienna) | Upward and Orthogonal Planarity are W[1]-hard Parameterized by Treewidth |
March 4 | Martin Dzúrik (Masaryk University) | Combinatorial Spectra of Graphs |
Upcoming speakers
April 3 | Mickael Randour (University of Mons) | |
April 15 | Samuel Braunfeld (Charles University) | |
April 22 | Niklas Schlomberg (University of Bonn) | |
May 6 | Kaushik Mallik (ISTA) | |
June 3 | Alexandru Malekshahian (King's College London) | |
June 10 | Felix Schröder (Charles University) |
Liana Khazaliya (TU Vienna): Upward and Orthogonal Planarity are W[1]-hard Parameterized by Treewidth
Monday, February 19, 14:00, room C417
Upward Planarity Testing and Orthogonal Planarity Testing are central problems in graph drawing. It is known that they are both NP-complete, but XP when parameterized by treewidth [Orthogonal: GD'19; Upward: SoCG'22]. In this talk, I will show that these two problems are W[1]-hard parameterized by treewidth, which answers open problems posed in two earlier papers. The key step in our proof is an analysis of the All-or-Nothing Flow problem, a generalization of which was used as an intermediate step in the NP-completeness proof for both planarity testing problems. We prove that the flow problem is W[1]-hard parameterized by treewidth on planar graphs, and that the existing chain of reductions to the planarity testing problems can be adapted without blowing up the treewidth. Our reductions also show that the known n^{O(tw)}-time algorithms cannot be improved to run in time n^{o(tw)} unless the Exponential Time Hypothesis fails.
Joint work with Bart M. P. Jansen, Philipp Kindermann, Giuseppe Liotta, Fabrizio Montecchiani, and Kirill Simonov
Martin Dzúrik (Masaryk University): Combinatorial Spectra of Graphs
Monday, March 4, 14:00, room C417
Combinatorial spectra of graphs is a generalization of H-Hamiltonian spectra. The main motivation was to made from H-Hamiltonian spectra an operation and develop some algebra in this field. An improved version of this operation form a commutative monoid. The most important thing is that most of the basic concepts of graph theory, such as maximum pairing, vertex and edge connectivity and coloring, Ramsey numbers, isomorphisms and regularity, can be expressed in the language of this operation.
Arxiv preprint avalilable here
Past terms
Spring 2021: Special Seminar – part of Round the World Relay in Combinatorics, where a number of seminars and groups around the world were getting together. Each site hosted a talk, and everyone was welcome.
Fall 2020: ITI Online Seminar – a one-semester online venue for presenting current research in discrete mathematics and theoretical computer science in the Czech Republic.