On the algebraic fundamental group of surfaces with K^2\leq 3\chi
Algebraic Geometry
2007-05-23 v3
Abstract
Let S be a minimal complex surface of general type with . We prove the following statements concerning the algebraic fundamental group: I) Assume that K^2_S\leq 3\chi(S). Then S has an irregular etale cover if and only if S has a free pencil of hyperelliptic curves of genus 3 with at least 4 double fibres. II) If K^2_S=3 and \chi(S)=1, then S has no irregular etale cover. III) If K^2_S<3\chi(S) and S does not have any irregular etale cover, then the order of the algebraic fundamental group is lesser or equal to 9, and if equality occurs then K^2_S=2, \chi(S)=1.
Keywords
Cite
@article{arxiv.math/0512483,
title = {On the algebraic fundamental group of surfaces with K^2\leq 3\chi},
author = {Margarida Mendes Lopes and Rita Pardini},
journal= {arXiv preprint arXiv:math/0512483},
year = {2007}
}
Comments
Final version, to appear in J.D.G