The moduli space of Keum-Naie surfaces

Abstract

Using a new description of Keum Naie surfaces and their fundamental group, we prove the following main result: Let S be a smooth complex projective surface which is homotopically equivalent to a Keum - Naie surface. Then S is a Keum - Naie surface. The connected component of the Gieseker moduli space corresponding to Keum - Naie surfaces is irreducible, normal, unirational of dimension 6.

20 pages revised version: minor changes, proof of theorem 2.1. corrected and largely simplified