Quasiconvex Subgroups and Nets in Hyperbolic Groups

نویسنده

  • THOMAS MACK
چکیده

Consider a hyperbolic group G and a quasiconvex subgroup H ⊂ G with [G : H] = ∞. We construct a set-theoretic section s : G/H → G of the quotient map (of sets) G → G/H such that s(G/H) is a net in G; that is, any element of G is a bounded distance from s(G/H). This section arises naturally as a set of points minimizing word-length in each fixed coset gH. The left action of G on G/H induces an action on s(G/H), which we use to prove that H contains no infinite subgroups normal in G.

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تاریخ انتشار 2006