Abstract.
By a result of Mukai, the non-abelian Brill-Noether locus X=M C (2, K : 3F) of type II, defined by a stable rank 2 vector bundle F of invariant 3 over a plane quartic curve C, is a prime Fano 3-fold X=X 16 of degree 16. The associate ruled surface S X=P(F) is uniquely defined by X, and we see that for the general X=X 16, S X is isomorphic to the Fano surface of conics on X. The argument uses the geometry of the Sp 3 -grassmannian and the double projection from a line on X 16.
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Partially supported by Grant MM-1106/2001 of the Bulgarian Foundation for Scientific Research
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Iliev, A. The Sp 3 -grassmannian and duality for prime Fano threefolds of genus 9. manuscripta math. 112, 29–53 (2003). https://doi.org/10.1007/s00229-003-0387-z
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DOI: https://doi.org/10.1007/s00229-003-0387-z