منابع مشابه
Rank Gradient of Cyclic Covers
If M is an orientable hyperbolic 3-manifold with finite volume and φ : π1(M) Z, the family of covers corresponding to {φ−1(nZ) |n ∈ N} has rank gradient 0 if and only if the Poincaré–Lefschetz dual of the class in H1(M ; Z) corresponding to φ is represented by a fiber. This generalizes a theorem of M. Lackenby. If M is closed, we give an explicit lower bound on the rank gradient. The proof uses...
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ژورنال
عنوان ژورنال: Pacific Journal of Mathematics
سال: 2013
ISSN: 0030-8730,0030-8730
DOI: 10.2140/pjm.2013.266.23