Motivated by our conjecture of an earlier work predicting the degeneration at the second page of
the Frölicher spectral sequence of any compact complex manifold supporting an SKT metric
(i.e., such that
), we prove
degeneration at
whenever the manifold admits a Hermitian metric whose torsion operator
and its adjoint vanish
on
-harmonic forms of
positive degrees up to
.
Besides the pseudodifferential Laplacian inducing a Hodge theory for
that we
constructed in earlier work and Demailly’s Bochner–Kodaira–Nakano formula for Hermitian
metrics, a key ingredient is a general formula for the dimensions of the vector spaces
featuring in the Frölicher spectral sequence in terms of the asymptotics, as a positive
constant
decreases to zero, of the small eigenvalues of a rescaled Laplacian
,
introduced here in the present form, that we adapt to the context of a complex
structure from the well-known construction of the adiabatic limit and from the
analogous result for Riemannian foliations of Álvarez López and Kordyukov.
Keywords
Frölicher spectral sequence, Hodge theory, Hermitian
metrics, elliptic differential and pseudodifferential
operators, spectral theory