Timeline for Subgroups of $GL_n(\mathbb Z)$ with finite coinvariants

9 events

when toggle format	what		by	license	comment
Jul 30, 2012 at 18:30	history	edited	Wilberd van der Kallen	CC BY-SA 3.0	improved phrasing
Jul 27, 2012 at 17:14	vote	accept	Igor Belegradek
Jul 27, 2012 at 17:14	vote	accept	Igor Belegradek
Jul 27, 2012 at 17:14
Jul 27, 2012 at 17:13	history	edited	Igor Belegradek	CC BY-SA 3.0	details added
Jul 27, 2012 at 16:43	comment	added	user6976		@Igor: $e_{i,j}(m)=e_{i,j}(1)^m$.
Jul 27, 2012 at 15:22	comment	added	Igor Belegradek		Oops. So how does one prove the claim in the first sentence of your answer?
Jul 27, 2012 at 15:19	comment	added	Wilberd van der Kallen		That will not work. They do not lie in $GL_n(\mathbb Z)$.
Jul 27, 2012 at 14:57	comment	added	Igor Belegradek		Thank you! In fact, it is enough to consider the diagonal matrices $E_i(m)$ which have $m$ at $(i,i)$ entry and $1$ on all other diagonal entries. I am still in the process of proving that the group generated by $E_1(m), \dots, E_n(m)$ sits in any given finite index subgroup for large $m$ but it does sound believable.
Jul 27, 2012 at 14:19	history	answered	Wilberd van der Kallen	CC BY-SA 3.0