2
$\begingroup$

The $(p,q,r)$ triangle group is the group with presentation $[a,b | a^p=b^q=(ab)^r=1]$. Has anyone classified the (infinite) quotients of the $(2,4,4)$ triangle group?

$\endgroup$
3
  • 8
    $\begingroup$ The triangle group in question has a normal subgroup of index 8 isomorphic to $\mathbb{Z}^2$. Therefore, any quotient has a normal subgroup of index at most 8 that's a quotient of $\mathbb{Z}^2$. How much more information do you need? $\endgroup$
    – HJRW
    Mar 4, 2011 at 3:55
  • 1
    $\begingroup$ So, in other words, yes. $\endgroup$ Mar 4, 2011 at 10:06
  • 1
    $\begingroup$ That subgroup of index 8 is the commutator, so every quotient has a commutator which is (i) of index at most 8 and (ii) a quotient of $\mathbb{Z}^2$. $\endgroup$
    – Steve D
    Mar 4, 2011 at 16:51

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Browse other questions tagged or ask your own question.