Abstract
This is a note for the conference proceedings Topological and Geometrical Problems related to Quantum Field Theory. We summarize our joint work with Dai about eta invariants on manifolds with boundary. Then we apply these results to prove the curvature and holonomy formulas for the natural connection on the determinant line bundle of a family of Dirac operators. These were originally proved by Bismut and the author--the proofs here are much simpler.