# Notation for Lie algebra Actions?

How can I do something like this:

This is to denote an action of G on H by means of D. I don't want the arrow to be too long.

Thanks.

Detexify proposes \curvearrowright from the amssymb package.
\documentclass{article}
$g\stackrel{D}{\curvearrowright}h$
$g\overset{D}{\curvearrowright}h$ % requires amsmath