English

A question about generalized nonvanishing

Algebraic Geometry 2024-05-17 v4

Abstract

Let (X,Δ)(X,\Delta) be a projective, Q\mathbb{Q}-factorial log canonical pair and let LL be a pseudoeffective Q\mathbb{Q}-divisor on XX such that KX+Δ+LK_X + \Delta + L is pseudoeffective. Is there an effective Q\mathbb{Q}-divisor MM on XX such that KX+Δ+LK_X + \Delta + L is numerically equivalent to MM? We are not aware of any counterexamples, but the answer is not completely clear even in the case of surfaces.

Cite

@article{arxiv.2312.09441,
  title  = {A question about generalized nonvanishing},
  author = {Claudio Fontanari},
  journal= {arXiv preprint arXiv:2312.09441},
  year   = {2024}
}

Comments

Final version, to appear in Rendiconti del Circolo Matematico di Palermo

R2 v1 2026-06-28T13:51:47.898Z