Intersection Graphs of geometric objects in the plane (mainly intersection graphs of curves and straight line segments).
Graph Drawing
Domination Theory - Perfect Domination (Perfect Codes) in general graphs, Telledomination in special classes of chordal graphs.
Covers of Graphs - mainly from the complexity point of view. Locally constrained graph homomorphisms, partial covers and the frequency assignment problem.
Induced Minors and related questions.
Hamiltonian Cycles in graphs and triangulations.
Graph Colorings - complexity of precoloring extension problems, list colorings, choosability, binding functions for chromatic number for special classes of graphs.
Distance constrained coloring - L(p,q) coloring of trees and graphs.
Hypergraph coloring - bicoloring clique hypergraphs of graphs, coloring mixed hypergraphs.
Satisfiability - computational complexity of various restricted versions of Satisfiability, studied in connection with the complexity of recognition of various interseciton graph classes.
See list of publications, my collaborators and the EUROCORES Collaborative Research Project GraDR EUROGIGA.