A p-group with positive rank gradient

作者:Schlage Puchta Jan Christoph*
来源:Journal of Group Theory, 2012, 15(2): 261-270.
DOI:10.1515/JGT.2011.101

摘要

We construct, for d %26gt;= 2 and epsilon %26gt; 0, a d-generated p-group Gamma which, in an asymptotic sense, behaves almost like a d-generated free pro-p-group. We show that a subgroup of index p(n) needs (d - epsilon)p(n) generators, and that the subgroup growth of Gamma satisfies s(p)(n)(Gamma) %26gt; s(p)(n)(F-d(p))(1-epsilon), where F-d(p) is the d-generated free pro-p-group. To do this we introduce a new invariant for finitely-generated groups and study some of its basic properties.

  • 出版日期2012-3