The multiple fibration problem for seifert 3-Orbifolds

ABSTRACT We conclude the multiple fibration problem for closed orientable Seifert three-orbifolds, namely, the determination of all the inequivalent fibrations that such an orbifold may admit. We treat here geometric orbifolds with geometries $\mathbb R^3$ and $\mathbb S^2\times\mathbb R$ and bad orbifolds (hence non-geometric), since the only other geometry for which the multiple fibration phenomenon occurs, namely, $\mathbb S^3$, has been treated before by the second and third authors. For the geometry $\mathbb R^3$ we recover, by direct and geometric arguments, the computer-assisted results obtained by Conway, Delgado-Friedrichs, Huson and Thurston.