Algebra Seminar

Tuesday, February 28, 2017 2:30 pm - 2:30 pm EST (GMT -05:00)

Adam Chapman, Tel-Hai Academic College, Israel

“Linked Fields of Characteristic 2 and their u-Invariant.”

The u-invariant of a field is the maximal dimension of a nonsingular anisotropic quadratic form over that field, whose order in the Witt group of the field is finite. By a classical theorem of Elman and Lam, the u-invariant of a linked field of characteristic different from 2 can be either 0,1,2,4 or 8. The analogous question in the case of characteristic 2 remained open for a long time. We will discuss the proof of the equivalent statement in characteristic 2, recently obtained in a joint work by Andrew Dolphin and the speaker.

MC 5413