Submission: 2008, May 18
We compute the essential dimension of Hermitian forms in the sense of O.Izhboldin. Apart from this we investigate the Chow motives of (twisted) incidence varieties and prove their incompressibility in dimensions $2^r-1$.
2000 Mathematics Subject Classification: 14C25
Keywords and Phrases: Chow motives, Hermitian form, incidence variety, Milnor hypersurface, incompressibility.
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