Xz. Dai et Ds. Freed, ETA-INVARIANTS AND DETERMINANT LINES, Comptes rendus de l'Academie des sciences. Serie 1, Mathematique, 320(5), 1995, pp. 585-591
We investigate the eta-invariant of an odd dimensional manifold with b
oundary. The exponential of the eta-invariant lives in the determinant
line of the boundary. Our main results are a variational formula and
a gluing law for this relative invariant. We apply these results to re
prove the formulae for the curvature and the holonomy of the natural c
onnection on the determinant line bundle of a family of Diract operato
rs.