Tuesday April 11

11:00  12:00 p.m.
 Registration and COFFEE 
12:00  2:00 p.m.
 LUNCH

2:00  3:00 p.m.
 Jan Kratochvil
Complexity of recognition of intersection graphs
Several classes of intersection graphs will be described. Complexity of
their recognition will be discussed, including a general technique for
showing NPhardness and questions about upper bounds. 
3:00  3:30 p.m.
 TEATIME 
3:30  4:30 p.m.
 Sue Whitesides
Complexity lower bounds for geometric representations of graphs
This talk will focus on a technique called the "logic engine", which has
proved useful for obtaining NPhardness results for geometric realization
problems for graphs. Several examples of the application of this technique
to proximity graph realization problems will be given. 
4:40  5:30 p.m.
 André Kündgen
Art gallery problems 
Wednesday, April 12

10:00  10:50 a.m.
 Petr Hlineny
Unitball contact graphs 
10:50  12:00 a.m.
 Informal session 1 
12:00  2:00 p.m.
 LUNCH 
2:00  3:00 p.m.
 Jan Kratochvil
Intersection representations of planar graphs and their complements
The question of representing planar graphs will be discussed, several
partial results and possible generalizations for surfaces of higher genus
will be surveyed. 
3:00  3:30 p.m.
 TEATIME 
3:30  4:30 p.m.
 Sue Whitesides
Some 2D visibility representation for graphs
This talk will focus on 2D representations of graphs in which the vertices
are represented as horizontal line segments and the edges are represented
as vertical lines of sight between these segments. 
4:30  5:30 p.m.
 Informal session 2

Thursday, April 13

10:00  11:00 a.m.
 Sue Whitesides
Some 3D visibility representations for graphs
This talk will focus on 3D representations of graphs in which the vertices
are represented as 2D objects floating in 3D parallel to the xyplane,
and the edges are represented as vertical lines of sight between these
objects. 
11:10  12:00 p.m.
 Informal session 3 
12:00  2:00 p.m.
 LUNCH

2:00  3:00 p.m.
 Jan Kratochvil
Optimization problems for intersection graphs
Some classes of intersection graphs allow fast (polynomial time) algorithms
for optimization problems such as coloring, maximum clique, maximum independent
set etc., that are NPcomplete for general graphs. We will discuss the
borderline between polynomially solvable and NPcomplete instances. The
theoretical question of bounding the chromatic number by a function of
the clique number will be also mentioned. 
3:00  3:30 p.m.
 TEA TIME 
3:30  4:30 p.m.
 Informal Session 4 
4:40  5:30 p.m.
 Informal Session 5 
Friday, April 14

Informal collaboration and discussions 