| | Combing nilpotent and polycyclic groups (Site not responding. Last check: 2007-11-02) |
 | | The notable exclusions from the family of automatic groups are those nilpotent groups which are not virtually abelian, and the fundamental groups of compact $3$-manifolds based on the $Nil$ or $Sol$ geometries. |
 | | It is shown that a finitely generated class 2 nilpotent group with cyclic commutator subgroup is real-time combable, as are also all 2 or 3-generated class 2 nilpotent groups, and groups in specific families of nilpotent groups (the finitely generated Heisenberg groups, groups of unipotent matrices over $\Z$ and the free class 2 nilpotent groups). |
 | | All the combings constructed in the article are boundedly asynchronous, and those for nilpotent-by-finite groups have polynomially bounded length functions, of degree equal to the nilpotency class, $c$; this verifies a polynomial upper bound on the Dehn functions of those groups of degree $c$+1. |
| www.mas.ncl.ac.uk /~nser/abstracts/nilpotent.html (271 words) |