Covering spaces of arithmetic 3-orbifolds

dc.creatorLackenby, Marc
dc.creatorLong, Darren D.
dc.creatorReid, Alan W.
dc.date2006-01-27
dc.date2008-04-09
dc.date.accessioned2026-07-07T09:31:08Z
dc.date.available2026-07-07T09:31:08Z
dc.descriptionLet G be an arithmetic Kleinian group, and let O be the associated hyperbolic 3-orbifold or 3-manifold. In this paper, we prove that, in many cases, G is large, which means that some finite index subgroup admits a surjective homomorphism onto a non-abelian free group. This has many consequences, including that O has infinite virtual first Betti number and G has super-exponential subgroup growth. Our first result, which forms the basis for the entire paper, is that G is commensurable with a lattice containing the Klein group of order 4. Our second result is that if G has a finite index subgroup with first Betti number at least 4, then G is large. This is known to hold for many arithmetic lattices. In particular, we show that it is always the case when G contains A_4, S_4 or A_5. Our third main result is that the Lubotzky-Sarnak conjecture and the geometrisation conjecture together imply that any arithmetic Kleinian group G is large. We also give a new 'elementary' proof that arithmetic Kleinian groups do not have the congruence subgroup property, which avoids the use of the Golod-Shafarevich inequality.
dc.description41 pages; v2: minor changes; to appear in IMRN
dc.identifierhttps://arxiv.org/abs/math/0601677
dc.identifierhttp://arxiv.org/abs/math/0601677
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/158356
dc.subjectGeometric Topology
dc.subject57N10 (Primary); 57M10, 57M50, 11F75 (Secondary)
dc.titleCovering spaces of arithmetic 3-orbifolds
dc.typetext

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