Zdenek Dvorak

Charles University

Circular and fractional chromatic number of sparse graphs

There are many results on variants of chromatic number (including the cricular and fractional chromatic number) in subclasses of planar graphs. Somewhat surprisingly, many of these results hold even under much weaker assumptions of sparseness. In this talk, I will give an overview of such results, and report on a progress in this area using the new method developed by Kostochka and Yancey in the setting of critical graphs.