Groups with small Dehn functions and bipartite chord diagrams

Abstract

We introduce a new invariant of bipartite chord diagrams and use it to construct the first examples of groups with Dehn function $n^2\log n$ and other small Dehn functions. Some of these groups have undecidable conjugacy problem.

39 pages; We added a section where we prove that multiple HNN extensions of free groups having undecidable conjugacy problem cannot have Dehn functions smaller than n^2 log n; 9/14/05 - made changes suggested by the referee. The paper is accepted in GAFA

Cited by in corpus (2)

• Groups with quadratic-non-quadratic Dehn functions
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