%0 Journal Article
%T Graph manifolds have virtually positive Seifert volume
%A Pierre Derbez
%A Shicheng Wang
%J Mathematics
%D 2009
%I arXiv
%R 10.1112/jlms/jdr085
%X This paper shows that the Seifert volume of each closed non-trivial graph manifold is virtually positive. As a consequence, for each closed orientable prime 3-manifold $N$, the set of mapping degrees $\c{D}(M,N)$ is finite for any 3-manifold $M$, unless $N$ is finitely covered by either a torus bundle, or a trivial circle bundle, or the 3-sphere.
%U http://arxiv.org/abs/0909.3489v1