Title: Homotopy invariants of Gauss phrases

Authors: Andrew Gibson

Issue: Volume 59 (2010), Issue 1, 207-230

Abstract: Equivalence relations can be defined on Gauss phrases using combinatorial moves. In this paper we consider two closely related equivalence relations on Gauss phrases, homotopy and open homotopy. In particular, in each case, we define a new invariant and determine the values that it can attain.