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In the mathematical subfield of 3-manifolds, the virtually fibered conjecture, formulated by American mathematician William Thurston, states that every closed, irreducible, atoroidal 3-manifold with infinite fundamental group has a finite cover which is a surface bundle over the circle. A 3-manifold which has such a finite cover is said to virtually fiber. If ''M'' is a Seifert fiber space, then ''M'' virtually fibers if and only if the rational Euler number of the Seifert fibration or the (orbifold) Euler characteristic of the base space is zero. The hypotheses of the conjecture are satisfied by hyperbolic 3-manifolds. In fact, given that the geometrization conjecture is now settled, the only case needed to be proven for the virtually fibered conjecture is that of hyperbolic 3-manifolds. The original interest in the virtually fibered conjecture (as well as its weaker cousins, such as the virtually Haken conjecture) stemmed from the fact that any of these conjectures, combined with Thurston's hyperbolization theorem, would imply the geometrization conjecture. However, in practice all known attacks on the "virtual" conjecture take geometrization as a hypothesis, and rely on the geometric and group-theoretic properties of hyperbolic 3-manifolds. The virtually fibered conjecture was not actually conjectured by Thurston. Rather, he posed it as a question and has stated that it was intended as a challenge (and not meant to indicate he believed it). The conjecture was finally settled in the affirmative in a series of papers from 2009 to 2012. In a posting on the ArXiv on 25 Aug 2009,〔Nicolas Bergeron and Daniel T. Wise, ''A boundary criterion for cubulation'', http://arxiv.org/abs/0908.3609〕 Daniel Wise implicitly implied (by referring to a then unpublished longer manuscript) that he had proven the conjecture for the case where the 3-manifold is closed, hyperbolic, and Haken. This was followed by a survey article in Electronic Research Announcements in Mathematical Sciences.〔Daniel T. Wise, ''Research announcement: The structure of groups with a quasiconvex hierarchy'', Electronic Research Announcements In Mathematical Sciences, V. 16, Pp 44–55 (October 29, 2009), S 1935-9179 AIMS (2009), http://www.aimsciences.org/journals/displayArticles.jsp?paperID=4703〕 Several more preprints 〔Haglund and Wise, ''A combination theorem for special cube complexes'', Hruska and Wise, ''Finiteness properties of cubulated groups'', Hsu and Wise, ''Cubulating malnormal amalgams'', http://comet.lehman.cuny.edu/behrstock/cbms/program.html 〕 have followed, including the aforementioned longer manuscript by Wise.〔Daniel T. Wise, ''The structure of groups with a quasiconvex hierarchy'', https://docs.google.com/file/d/0B45cNx80t5-2NTU0ZTdhMmItZTIxOS00ZGUyLWE0YzItNTEyYWFiMjczZmIz/edit?pli=1〕 In March 2012, during a conference at Institut Henri Poincaré in Paris, Ian Agol announced he could prove the virtually Haken conjecture for closed hyperbolic 3-manifolds .〔Ian Agol, ''The virtual Haken conjecture'', http://arxiv.org/abs/1204.2810〕 Taken together with Daniel Wise's results, this implies the virtually fibered conjecture for all closed hyperbolic 3-manifolds. ==Notes== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Virtually fibered conjecture」の詳細全文を読む スポンサード リンク
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