TITLE: does every right-angled coxeter group have a right-angled artin group as a subgroup of finite index?
QUESTION [8 upvotes]: I thought that I read a paper making this claim a few months ago, but now I can't find it.  If the answer is yes, is there a nice way to go from the presentation of the right-angled coxeter group to a presentation of its right-angled artin subgroup?  Thanks.

REPLY [13 votes]: As James points out, the paper of Davis and Januskiewicz proves the inverse.  To see that the answer to your question is 'no', consider the right-angled Coxeter group whose nerve graph is a pentagon.  That is, it's the group with presentation
$\langle a_1,\ldots, a_5 \mid a_i^2=1, [a_i,a_{i+1}]=1\rangle$
where the indices are considered mod 5.
This group acts properly discontinuously and cocompactly on the hyperbolic plane, and it's not hard to see that it has a finite-index subgroup which is the fundamental group of a closed hyperbolic surface.  Every finite-index subgroup of a right-angled Artin group is either free or contains a copy of $\mathbb{Z}^2$, but the fundamental group of a closed hyperbolic surface has no finite-index subgroups of this form.