Dienstag, 18.03.2025, 12:00 Uhr, , SR 055, Takustraße 9 Robert Scheffler (BTU Cottbus)zum Thema: Simultaneous Representations meet Graph Width Parameters: The Simultaneous Interval Number and the Simultaneous Chordal Number
Abstract:We propose a novel way of generalizing the classes of interval and chordal graphs via graph width parameters called simultaneous interval number and simultaneous chordal number. These parameters are related to the simultaneous representation problem for interval (chordal) graphs and are defined as the smallest number d of labels such that the graph admits a d-simultaneous interval (chordal) representation, that is, an assignment of intervals (subtrees of a tree) and label sets to the vertices such that two vertices are adjacent if and only if the corresponding intervals (subtrees) as well as their label sets intersect. We discuss the complexity of computing these parameters and give several bounds for the parameters, showing in particular their relation to pathwidth and treewidth. Furthermore, we discuss FPT algorithms and hardness results for problems like Clique, Independent Set, Dominating Set and Coloring.