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Cohomological splitting criterion on Lagrangian Grassmannians

Develop a cohomological splitting criterion for vector bundles on the Lagrangian Grassmannian LG(k), valid for any k ≥ 1, that characterizes when a bundle splits as a direct sum of line bundles—potentially using vanishing conditions involving irreducible homogeneous bundles rather than only wedge powers.

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Background

For Grassmannians Gr(Pk, Pn), Ottaviani (1989) proved a splitting criterion that characterizes sums of line bundles via cohomology vanishings involving Schur functors of the universal bundle. For LG(k), Oeding–Macias Marques (2009) established partial results: their vanishing condition implies splitting, and the converse holds for k ≤ 6, but fails for k = 7 for E = O.

The authors highlight that LG(k) remains an open case for finding a general splitting criterion analogous to Grassmannians, suggesting the likely need to use irreducible homogeneous bundles (maximal weights) rather than only wedge powers.

References

Question 1.17. Can be found a cohomological splitting criterion on LG(k) for any k ? One should likely use irreducible homogeneous bundles (with the language of maximal weights) and not just products of wedge powers.

Vector bundles without intermediate cohomology and the trichotomy result (2402.07254 - Ottaviani, 11 Feb 2024) in Question 1.17 (Section 1.4)