karpenko at ualberta.ca
Submission: 2014, Aug 22
We consider a central division algebra over a separable quadratic extension of a base field endowed with a unitary involution and prove 2-incompressibility of certain varieties of isotropic right ideals of the algebra. The remaining related projective homogeneous varieties are shown to be 2-compressible in general. Together with , where a similar issue for orthogonal and symplectic involutions has been treated, the present paper completes the study of grassmannians of isotropic ideals of division algebras.
 Karpenko, N. A. Orthogonal and symplectic Grassmannians of division algebras. J. Ramanujan Math. Soc. 28 (2013), no. 2, 213--222.
2010 Mathematics Subject Classification: 14L17; 14C25
Keywords and Phrases: Algebraic groups, quadratic forms, projective homogeneous varieties, Chow groups and motives.
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