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Equivalence of inner cohomology vanishing and Fano projectivization on Fano varieties

Determine whether, for any Fano variety X of dimension at least 4 (beyond projective spaces P^n and smooth quadrics Q^n), the following two conditions on a rank-2 vector bundle E on X are equivalent: (i) H^i(X, E(t)) = 0 for all integers t and for 2 ≤ i ≤ dim X − 2 (i.e., E has no inner cohomology), and (ii) the projectivized bundle P(E) is Fano.

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Background

Theorem 1.9 (Ancona-Peternell-Wisniewski, Malaspina) establishes that for X = Pn or X = Qn (n ≥ 4), three conditions on a rank-2 bundle E are equivalent: (1) E has no inner cohomology (vanishing Hi(E(∗)) for 2 ≤ i ≤ n − 2), (2) the projectivization P(E) is Fano, and (3) E splits as O(a)⊕O(b) or belongs to a small list of special bundles (including spinor bundles on Q4).

The authors ask whether the equivalence between the first two conditions—vanishing of inner cohomology and P(E) being Fano—extends to other Fano varieties of dimension ≥ 4, noting that their proof of equivalence on Pn and Qn proceeds indirectly via the third condition.

References

Question 1.10. Are the first two items equivalent on other Fano varieties of dimension ≥ 4 ? Note that the proof of the equivalence on P and Q is innirect, through the third item.

Vector bundles without intermediate cohomology and the trichotomy result (2402.07254 - Ottaviani, 11 Feb 2024) in Question 1.10 (following Theorem 1.9, Section 1.3)