The Atiyah–Patodi–Singer rho invariant and signatures of links

Abstract

AbstractRelations between the Atiyah–Patodi–Singer rho invariant and signatures of links have been known for a long time, but they were only partially investigated. In order to explore them further, we develop a versatile cut-and-paste formula for the rho invariant, which allows us to manipulate manifolds in a convenient way. With the help of this tool, we give a description of the multivariable signature of a link$L$as the rho invariant of some closed three-manifold$Y_L$intrinsically associated with$L$. We study then the rho invariant of the manifolds obtained by the Dehn surgery on$L$along integer and rational framings. Inspired by the results of Casson and Gordon and Cimasoni and Florens, we give formulas expressing this value as a sum of the multivariable signature of$L$and some easy-to-compute extra terms.