During the past few decades, the gradual merger of Discrete Geometry and the newer discipline of Computational Geometry has provided enormous impetus to mathematicians and computer scientists interested in geometric problems. This volume, which contains 32 papers on a broad range of topics of current interest in the field, is an outgrowth of that synergism. It includes surveys and research articles exploring geometric arrangements, polytopes, packing, covering, discrete convexity, geometric algorithms and their complexity, and the combinatorial complexity of geometric objects, particularly in low dimension.

### Contents

1. Geometric approximation via core sets Pankaj K. Agarwal, Sariel Har-Peled and Kasturi Varadarajan; 2. Applications of graph and hypergraph theory in geometry Imre Barany; 3. Convex geometry of orbits Alexander Barvinok and Grigoriy Blekherman; 4. The Hadwiger transversal theorem for pseudolines Saugata Basu, Jacob E. Goodman, Andreas Holmsen and Richard Pollack; 5. Betti number bounds, applications, and algorithms Saugata Basu, Richard Pollack and Marie-Francoise Roy; 6. Shelling and the h-vector of the (extra-)ordinary polytope Margaret M. Bayer; 7. On the number of mutually touching cylinders Andras Bezdek; 8. Edge-antipodal 3-polytopes Karoly Bezdek, Tibor Bisztriczky and Karoly Boroczky; 9. A conformal energy for simplicial surfaces Alexander Bobenko; 10. On the size of higher-dimensional triangulations Peter Brass; 11. The carpenter's ruler folding problem Gruia Calinescu and Adrian Dumitrescu; 12. A survey of folding and unfolding in computational geometry Erik D. Demaine and Joseph O'Rourke; 13. On the rank of a tropical matrix Mike Develin, Francisco Santos and Bernd Sturmfels; 14. The geometry of biomolecular solvation Herbert Edelsbrunner and Patrice Koehl; 15. Inequalities for zonotopes Richard G. Ehrenborg; 16. Quasiconvex programming David Eppstein; 17. De Concini-Procesi wonderful arrangement models - a discrete geometer's point of view Eva Maria Feichtner; 18. Thinnest covering of a circle by eight, nine, or ten congruent circles Gabor Fejes Toth; 19. On the complexity of visibility problems with moving viewpoints Peter Gritzmann and Thorsten Theobald; 20. Cylindrical partitions of convex bodies Aladar Heppes and Wlodzimierz Kuperberg; 21. Tropical halfspaces Michael Joswig; 22. Two proofs for Sylvester's problem using an allowable sequence of permutations Hagit Last; 23. A comparison of five implementations of 3d Delaunay tessellation Yuanxin Liu and Jack Snoeyink; 24. Bernstein's basis and real root isolation Bernard Mourrain, Fabrice Rouillier and Marie-Francoise Roy; 25. On some extremal problems in combinatorial geometry Niranjan Nilakantan; 26. A long non-crossing path among disjoint segments in the plane Janos Pach and Rom Pinchasi; 27. On a generalization of Schoenhardt's polyhedron Joerg Rambau; 28. On Hadwiger numbers of direct products of convex bodies Istvan Talata; 29. Binary space partitions - recent developments Csaba D. Toth; 30. Erdos-Szekeres theorem: upper bounds and related results Geza Toth and Pavel Valtr; 31. On the pair-crossing number Pavel Valtr; 32. Geometric random walks: a survey Santosh Vempala.