Real Graded Brauer and Witt groups
Real Graded Brauer and Witt groups

Chuck Weibel, Rutgers University
Fine Hall 214
If X is a topological space with involution, we can use Atiyah's Real vector bundles to define analogues of the Witt group and BrauerWall groups in algebra. They are easier to compute than their algebraic cousins, because they are finitely generated and related to Borel cohomology. If V is an algebraic variety defined over the real numbers, the BrauerWall group of V is the direct sum of the Real graded Brauer group of the associated space with involution and a divisible group; they are isomorphic if V is smooth projective and the Hodge number h^{0,2} is zero.