Zusammenfassung

On the universal bundle of unit spinors we study a natural energy
functional whose critical points, if dimM C 3, are precisely the pairs (g,φ) consisting
of a Ricci-flat Riemannian metric g together with a parallel g-spinor φ.
We investigate the basic properties of this functional and study its negative
gradient flow, the so-called spinor flow. In particular, we prove short-time
existence and uniqueness for this flow.