Paper surfaces and dynamical limits

It is very common in mathematics to construct surfaces by identifying the sides of a polygon together in pairs: For example, identifying opposite sides of a square yields a torus. In this article the construction is considered in the case where infinitely many pairs of segments around the boundary of the polygon are identified. The topological, metric, and complex structures of the resulting surfaces are discussed: In particular, a condition is given under which the surface has a global complex structure (i.e., is a Riemann surface). In this case, a modulus of continuity for a uniformizing map is given. The motivation for considering this construction comes from dynamical systems theory: If the modulus of continuity is uniform across a family of such constructions, each with an iteration defined on it, then it is possible to take limits in the family and hence to complete it. Such an application is briefly discussed.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

FAPESP Fundacao de Amparo a Pesquisa do Estado de Sao Paulo[2006/03829-2]

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

CNPq Conselho Nacional de Desenvolvimento Cientifico e Tecnologico[151449/2008-2]