It is proved that the Freudenthal compactification of an open, connected, oriented 3-manifold is a 3-fold branched covering of S3, and in some cases, a 2-fold branched covering of S3. The branching set is a locally finite disjoint union of strings.
La compactificación de Freudenthal de una 3-variedad abierta conexa y orientable es una cubierta de 3 hojas ramificada sobre S3 y, en ciertos casos, de dos hojas. La ramificación es una unión localmente finita y disjunta de cuerdas.
@article{urn:eudml:doc:44368,
title = {Representing open 3-manifolds as 3-fold branched coverings.},
journal = {Revista Matem\'atica de la Universidad Complutense de Madrid},
volume = {15},
year = {2002},
pages = {533-542},
zbl = {1023.57002},
mrnumber = {MR1951824},
language = {en},
url = {http://dml.mathdoc.fr/item/urn:eudml:doc:44368}
}
Montesinos-Amilibia, José María. Representing open 3-manifolds as 3-fold branched coverings.. Revista Matemática de la Universidad Complutense de Madrid, Tome 15 (2002) pp. 533-542. http://gdmltest.u-ga.fr/item/urn:eudml:doc:44368/