Subgroup distortion (source code)

= Subgroup distortion
{wiki=Distortion_(mathematics)#Subgroup_distortion}

For a finitely generated subgroup $H\leq G$, subgroup distortion compares the intrinsic word length $|h|_H$ with the ambient word length $|h|_G$. The subgroup is undistorted exactly when its inclusion is a <quasi-isometric embedding>.