1
$\begingroup$

Let $\mathbb{F}_{p}$ be a finite field of order $p$, and $\mathbb{F}_{p}[[T]]$ be the ring of formal power series over $\mathbb{F}_{p}$. My question is the following:

Let $G$ be a closed pro-$p$ subgroup of ${\rm GL}_{n}(\mathbb{F}_{p}[[T]])$. Suppose that $G$ is topologically finitely generated and $G$ is torsion-free. Is it true that $G$ is solvable?

$\endgroup$
1
  • $\begingroup$ I'd guess the answer is no at least for $n\ge 3$. Namely considering SO of a quadratic anisotropic form. This is a compact subgroup and I expect it to be virtually torsion-free (but has an abstract free subgroup). For $n=2$ an SU2-like subgroup might do the job, using that we can view $F_p((t))$ as quadratic extension of $F_p((t^2))$ to define an anisotropic Hermitian form. $\endgroup$
    – YCor
    Dec 10 at 5:33

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.