Curves on irrational ruled surfaces whose complements are of non-general type
Algebraic Geometry
2026-06-27 v1
Abstract
Let be a curve on an irrational ruled surface . We prove that the logarithmic Kodaira dimension of equals the Iitaka dimension of and give a rough configuration of when the logarithmic Kodaira dimension of is less than two. Next, we study the logarithmic multicanonical system of when the logarithmic Kodaira dimension of equals one and prove that its logarithmic -canonical system gives either a -fibration or an elliptic fibration if .
Keywords
Cite
@article{arxiv.2606.28803,
title = {Curves on irrational ruled surfaces whose complements are of non-general type},
author = {Hideo Kojima},
journal= {arXiv preprint arXiv:2606.28803},
year = {2026}
}
Comments
21 pages, one figure