Ketu and the second invariant of a quadratic space

Using the Chern classes defined by Grothendieck, we map aK-theoretic invariant of invertible symmetric matrices defined by Giffen to the Clifford invariant.According to Herrmann Graßman'sWörterbuch zum Rig-veda, Ketu may not be connected with K₂ but es bezeichnet das, was sich sichtbar oder kenntlich macht ...     

Rationally trivial hermitian spaces are locally trivial

Let R be a regular local ring, K its field of fractions and A an Azumaya algebra with involution over R. Let h be an -hermitian space over A. We show that if is hyperbolic over , then h is hyperbolic over A. Received September 28, 1998; in final form December 6, 1999 / Published online March 12, 2001     

The Clifford algebra of a metabolic space

The authors thank the Department of Mathematics of the University of Pisa for the hospitality accorded during the preparation of this paper.