Kohomolojik boyut ve üçüncü derece yüzeyler

ABSTRACTCOHOMOLOGICAL DIMENSION AND CUBICSURFACES˙Inan Utku TürkmenuM.S. in MathematicsSupervisor: Assoc. Prof. Dr. Ali Sinan SertüzoAugust, 2004In this thesis we give necessary and sufficient conditions for a curve C on a givencubic surface Q so that Q − C is affine. We use this to give a simpler proof ofcd(P3 − C) = 1 by using Budach?s method for these curves.We investigate thenature of curves on cubic surfaces such that the cubic surface minus these curvesis an affine variety. We give combinatorial conditions for the existence of suchcurves.Keywords: Cohomological dimension, Del Pezzo surfaces, Cubic surfaces, Inter-section Theory.iii