The additivity of the -invariant and periodicity in topological surgery
arXiv:1002.1917 · doi:10.2140/agt.2011.11.1915
Abstract
For a closed topological manifold M with dim (M) >= 5 the topological structure set S(M) admits an abelian group structure which may be identified with the algebraic structure group of M as defined by Ranicki. If dim (M) = 2d-1, M is oriented and M is equipped with a map to the classifying space of a finite group G, then the reduced rho-invariant defines a function, \wrho : S(M) \to \QQ R_{hat G}^{(-1)^d}, to a certain sub-quotient of the complex representation ring of G. We show that the function \wrho is a homomorphism when 2d-1 >= 5. Along the way we give a detailed proof that a geometrically defined map due to Cappell and Weinberger realises the 8-fold Siebenmann periodicity map in topological surgery.
arXiv commentContains minor corrections suggested by the referee and also more details in the proofs of Proposition 2.9 and Lemma 8.1 and an explanation in Remark 2.10