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The geometry of open continuous mappings having two valences between Riemann surfaces

Published online by Cambridge University Press:  24 October 2008

Abdallah Lyzzaik
Affiliation:
Department of Mathematics, American University of Beirut, Beirut, Lebanon

Abstract

An open continuous function from an open Riemann surface with finite genus and finite number of boundary components into a closed Riemann surface is termed a (p, q)-map, 0 < q < p, if it has a finite number of branch points and assumes every point in the image surface either p or q times, counting multiplicity, with possibly a finite number of exceptions.

The object of this paper is to prove that the geometry of any (p, q)-map resembles that of a (p, q)-map whose q-set (the set of image points of f that are taken on exactly q times, counting multiplicity), constitutes a finite set of Jordan arcs or curves (loops). This leads to interesting geometrie results regarding (p, q)-maps without exceptional points. Further, it yields that every (p, q)-map is homotopic to a simplicial (p, q)-map having the same covering properties.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1996

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References

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