Spineurs, opérateurs de Dirac et variations de métriques. (Spinors, Dirac operators and variations of the metrics) (Q1189239)

The construction of a spinor bundle over a Riemannian spin manifold depends on the given metric. In this article a geometric process to compare spinor fields for different metrics is described. As an application one can study how the eigenvalues of the Dirac operator depend on the metric. A few cases are discussed in which the eigenvalues are critical for arbitrary volume preserving variations of the metric.