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UNITARY GRASSMANNIANS OF DIVISION ALGEBRAS

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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 [17], where a similar issue for orthogonal and symplectic involutions has been treated, the present paper completes the study of Grassmannians of isotropic right ideals of division algebras.

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  1. Mathematical & Statistical Sciences, University of Alberta, Edmonton, Canada

    NIKITA A. KARPENKO

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KARPENKO, N.A. UNITARY GRASSMANNIANS OF DIVISION ALGEBRAS. Transformation Groups 21, 115–127 (2016). https://doi.org/10.1007/s00031-015-9337-6

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