Bulletin of the London Mathematical Society Advance Access published online on May 22, 2009
Bulletin of the London Mathematical Society, doi:10.1112/blms/bdp041
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© 2009 London Mathematical Society
Free centre-by-nilpotent-by-abelian groups
School of Mathematics
University of Manchester
Manchester
M13 9PL
United Kingdom
marianne.johnson@maths.manchester.ac.uk
Received 21 April 2008. Revision received 6 January 2009.
We prove that the free centre-by-(nilpotent-of-class-(c–1))-by-abelian groups F/[
c(F'), F] are torsion-free for c=6. This is in startling contrast to the cases when c is a prime and when c=4, where these relatively free groups contain non-trivial elements of finite order.
2000 Mathematics Subject Classification 20J05, 20E22.