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Deformation Theory Seminar

Wednesday, November 20, 2002 - 2:00pm

John Rosson

Millersville U

Location

University of Pennsylvania

4C4 DRL

New expanded abstract

Two n-complexes (in this case, dimension n or less) are simply homotopic if one can move from one to the other via cell expansions and collapses; together: deformations. A +1deformation of a complex is one in which the dimension of the expansion cells is at most n+1. These moves define equivalence relations on n-complexes and it is known (for all dimensions except 2) that simple homotopy equivalence is the same as +1deformation equivalence. The Andrews-Curtis Conjecture (AC) states that this is also true in dimension 2. The AC is interesting because it is a necessary condition for the Poincare Conjecture. We discuss the work of Wolfgang Metzler, Cynthia Hog-Angeloni on stabilization and potential counter-examples to AC (and therefore Poincare). Because of stabilization, the usual topological invariants cannot tell us if potential counter-examples are actual counter-examples. Based on the work of Serge Matveev on special 2-complexes, we construct algebraic invariants of AC classes which generalize Frank Quinn's TQFT invariants. These escape stabilizaton i.e. if they are "non-zero" on potential counter-examples, we have an actual counter-example