Log-canonical threefold abundance in numerical dimension one. Proves log abundance for projective log canonical threefold pairs over algebraically closed fields of characteristic p > 3 when the effective boundary is rational and the ℚ-Cartier adjoint is nef of numerical dimension one. The adjoint is semiample, without requiring the original variety to be terminal or ℚ-factorial.
released 2026-10-05 | 2 theorems · 2 lemmas · 9 proofs · 7,828 words |
PLAY LEVEL 1 »(pdf)
We prove the numerical-dimension-one case of log abundance for threefolds over algebraically closed fields of characteristic p > 3. If $(X,B)$ is a projective log canonical threefold pair with effective rational boundary, and $K_X+B$ is ℚ-Cartier, nef, and of numerical dimension one, then $K_X+B$ is semiample. Neither terminality nor ℚ-factoriality of X is required.
released 2026-09-24 | 2 theorems · 19 lemmas · 29 proofs · 21,963 words |
PLAY LEVEL 2 »(pdf)
Let X be a projective ℚ-factorial terminal threefold over an algebraically closed field of characteristic p > 3. We prove the numerical-dimension-one case of abundance: if KX is nef with $\nu(K_X)=1$, then KX is semiample and $\kappa(X,K_X)=1$.