Mapping tori with first Betti number at least two
نویسندگان
چکیده
منابع مشابه
“ L 2 - Betti numbers of mapping tori and groups ” by
We prove the following two conjectures of Gromov. Firstly, all L2-Betti numbers of a manifold fibered over S1 are trivial. Secondly, the first L2-Betti number of a finitely presented group Γ vanishes provided that Γ is an extension {1} −→ ∆ −→ Γ −→ π −→ {1} of finitely presented groups such that ∆ is infinite and π contains Z as a subgroup. We conclude for such a group Γ that its deficiency is ...
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ژورنال
عنوان ژورنال: Journal of the Mathematical Society of Japan
سال: 2007
ISSN: 0025-5645
DOI: 10.2969/jmsj/05920351