Talk:Thurston norm

First draft
As it stands this is incomplete. Stuff I'd like to add: jraimbau (talk) 10:00, 8 July 2016 (UTC)
 * a description of Agol's work on RFRS and virtual fibrations, in
 * the relation with Alexander polynomials found by McMullen and ameliorated by Harvey (see ))

Euler characteristic
Isn't the Euler characteristic of a sphere 2? Why is it 0 in this case? Or do I miss something? oh wait, $$\chi_-(S^2) = \max (0,-2) = 0$$... Wilson868 (talk) 10:13, 8 June 2019 (UTC)