On degenerations of Z/2-Godeaux surfaces
No Thumbnail Available
Date
2022
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
We compute equations for the Coughlan's family of Godeaux surfaces with torsion Z/2, which we call Z/2-Godeaux surfaces, and we show that it is (at most) 7 dimensional. We classify all non-rational KSBA degenerations W of Z/2-Godeaux surfaces with one Wahl singularity, showing that W is birational to particular either Enriques surfaces, or D-2,D-n elliptic surfaces, with n = 3, 4 or 6. We present examples for all possibilities in the first case, and for n = 3, 4 in the second.