On Z/3-Godeaux surfaces
Algebraic Geometry
2016-09-09 v1
Abstract
We prove that Godeaux--Reid surfaces with torsion group Z/3 have topological fundamental group Z/3. For this purpose, we describe degenerations to stable KSBA surfaces with one 1/4(1,1) singularity, whose minimal resolution are elliptic fibrations with two multiplicity 3 fibres and one I_4 singular fibre. We study special such degenerations which have an involution, describing the corresponding Campedelli double plane construction. We also find some stable rational degenerations, some of which have more singularities, and one of which has a single 1/9(1,2) singularity, the minimal possible index for such a surface. Finally, we do the analogous study for the Godeaux surfaces with torsion Z/4.
Cite
@article{arxiv.1609.02177,
title = {On Z/3-Godeaux surfaces},
author = {Stephen Coughlan and Giancarlo Urzúa},
journal= {arXiv preprint arXiv:1609.02177},
year = {2016}
}