On Singular Complex Surfaces with Negative Canonical Bundle, with Applications to Singular Compactifications of C2 and to 3-Dimensional Rational Singularities.
This is the text of a talk given at the XVII Convegno dellUnione Matematica Italiana held at Milano, September 8-13, 2003. I would like to thank Angelo Lopez and Ciro Ciliberto for the kind invitation to the conference. I survey some numerical conjectures and theorems concerning relations between the index, the pseudo-index and the Picard number of a Fano variety. The results I refer to are contained in the paper [3], wrote in collaboration with Bonavero, Debarre and Druel.
We discuss the problem of stable conjugacy of finite subgroups of Cremona groups. We compute the stable birational invariant H 1(G, Pic(X)) for cyclic groups of prime order.
The moduli space M of surfaces of general type with pg = q = 1, K2 = g = 3 (where g is the genus of the Albanese fibration) was constructed by Catanese and Ciliberto in [14]. In this paper we characterize the subvariety M2 ⊂ M corresponding to surfaces containing a genus 2 pencil, and moreover we show that there exists a non-empty, dense subset M0 ⊂ M which parametrizes isomorphism classes of surfaces with birational bicanonical map.
This paper classifies surfaces of general type with having an involution such that has non-negative Kodaira dimension and that the bicanonical map of factors through the double cover induced by It is shown that is regular and either: a) the Albanese fibration of is of genus 2 or b) has no genus 2 fibration and is birational to a surface. For case a) a list of possibilities and examples are given. An example for case b) with is also constructed.