Distortion of embeddings of a torsion-free finitely generated nilpotent group into a unitriangular group

In this paper we study distortion of various well-known embeddings of finitely generated torsion-free nilpotent groups $G$ into unitriangular groups $UT_n(\mathbb{Z})$. We also provide a polynomial time algorithm for finding distortion of a given subgroup of $G$Comment: 27 page