On Rho invariants of fiber bundles

Michael Bohn

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arXiv · 0907.3530

On Rho invariants of fiber bundles

Michael Bohn

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Abstract

Using adiabatic limits of Eta invariants, Rho invariants of the total space of a fiber bundle are investigated. One concern is to formulate the aspects of local index theory for families of Dirac operator in terms of the odd signature operator, and place known results in a context which permits the treatment of Rho invariants. The main focus is, however, to use this to compute Rho invariants for explicit classes of fibered 3-manifolds. More precisely, we consider $\U(1)$-Rho invariants of principal $S^1$-bundles over closed, oriented surfaces as well as mapping tori with torus fiber. Hyperbolic monodromy maps deserve particular attention. When discussing them, the logarithm of a generalized Dedekind Eta function naturally appears. An explicit formula for $\U(1)$-Rho invariants is then deduced from a transformation formula for these Dedekind Eta functions.

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Michael Bohn. 2009-07-21. On Rho invariants of fiber bundles. https://arxiv.org/abs/0907.3530

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