Fino–Vezzoni conjecture on balanced and pluriclosed Hermitian metrics

Determine whether every compact complex manifold admitting both a balanced Hermitian metric and a pluriclosed Hermitian metric necessarily admits a Kähler metric.

Background

The Fino–Vezzoni conjecture concerns the coexistence of two potentially distinct Hermitian metrics on the same compact complex manifold: one satisfying the balanced condition d(ω{n−1}) = 0 and another satisfying the pluriclosed condition ∂∂̄ω = 0. The conjecture asserts that this coexistence forces the underlying complex manifold to admit a Kähler metric.

The paper proves the conjecture under the additional assumption that the balanced Hermitian metric is Bismut torsion-parallel, thereby resolving the balanced BTP subclass in every complex dimension. The unrestricted conjecture stated in Conjecture 1 is broader than the theorem proved in the paper and remains the relevant unresolved problem.

References

Conjecture 1 (Fino-Vezzoni, [11, 12]). Let M n be a compact complex manifold. If M admits a balanced Hermitian metric and a pluriclosed Hermitian metric, then M admits a Kähler metric.

The Fino-Vezzoni conjecture on balanced Bismut torsion-parallel manifolds  (2608.13887 - Chen et al., 14 Aug 2026) in Conjecture 1, Section 1, page 1