Full paper in PDF:
$%I. C. Garijo, Riemann and Klein surfaces with nodes viewed as quotients, Rev. Mat. Complut. 19 (2006), no. 1, 145–159.%$

Riemann and Klein Surfaces with Nodes Viewed as Quotients
Ignacio C. GARIJO
Dpto. de Matemáticas Fundamentales
Facultad de Ciencias, UNED
c/ Senda del Rey, 9
28040 Madrid — Spain
 igarijo@mat.uned.es

Received: March 10, 2005
Accepted: October 10, 2005
ABSTRACT

If G is a group of automorphisms that acts properly discontinuously on a Riemann or Klein surface X , then there exists a unique structure of Riemann or Klein surface on X/G such that the projection p :X --> X/G 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.