Mumford's nonvanishing conjecture for pseudoeffective canonical bundles

Let XX be a complex projective manifold, and let KXK_X denote its canonical bundle. A line bundle is pseudoeffective when its numerical class lies in the closure of the cone of effective divisor classes. Write ΩX1\Omega^1_X for the cotangent bundle. Mumford's nonvanishing conjecture. If KXK_X is pseudoeffective, then there exists a positive integer mm such that

H0(X,(ΩX1)m)0.H^0\big(X,(\Omega^1_X)^{\otimes m}\big)\neq 0.

This formulation is equivalent to Mumford's characterization because a projective manifold is uniruled if and only if its canonical bundle is not pseudoeffective. The conjecture is known in several cases, including when the numerical dimension of the canonical bundle is zero or maximal, but remains open in general.

Sources & referencesView supporting material

Primary source

Vladimir Lazić and Thomas Peternell, “Rationally connected varieties - on a conjecture of Mumford”, arXiv:1608.04706 (2016).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.