Full paper in PDF:
$%I. C. Garijo, Riemann and Klein surfaces with nodes viewed as quotients, Rev. Mat. Complut. 19
(2006), no. 1, 145–159.%$
If is a group of automorphisms that acts properly discontinuously on a Riemann or Klein surface , then there exists a unique structure of Riemann or Klein surface on such that the projection is a morphism. The analogous result is not true when we deal with surfaces with nodes. In this paper we give a new definition of a group that acts properly discontinuously on a surface with nodes in order to obtain a similar theorem.
Key words: Riemann surfaces with nodes, Klein surfaces with nodes, groups of
automorphisms.
2000 Mathematics Subject Classification: 30F50, 30F10, 20H10, 20H15.