Pseudo-Visibility Graphs

by Mr Bodhayan Roy (School of Technology and Computer Science)

Tuesday 8 Mar 2011, 17:00 → 18:00 Asia/Kolkata

A-212 (Colaba Campus)

The notion of visibility graphs can be extended to that of pseudo-visibility graphs, where the edges between vertices do not necessarily remain straight line-segments. We discuss the construction of pseudo-visibility graphs which cannot be drawn on the plane as any valid visibility graph keeping the polygonal boundary unaltered, even though they satisfy all the necessary combinatorial conditions known for a graph to be a visibility graph. This proves that the necessary conditions are not sufficient ones.