Unramified Cohomology of Quadrics, Ii
نویسنده
چکیده
We compute the unramified cohomology of quadrics of dimension 4 in degree 4 over an arbitrary field of characteristic different from 2. We find that it is related to classical invariants of a more elementary nature, such as the group of spinor norms and the projective special orthogonal group modulo Manin’s R-equivalence.
منابع مشابه
Unramified Cohomology of Quadrics, Iii
This paper is the third and last instalment of our project of computation of the low-degree unramified cohomology of quadrics. As in the previous papers [15] and [16], we denote by η X the map H(F,Q/Z(n− 1))→ H nr(F (X)/F,Q/Z(n− 1)) for a smooth, projective quadric X defined over a field F of characteristic 6= 2. Recall that in these papers we proved that Ker η X is generated by symbols for n ≤...
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