English

An algebraic proof of Iitaka's Conjecture C_{2,1}

Algebraic Geometry 2007-05-23 v1

Abstract

We give a proof of Iitaka's Conjecture C_{2,1} using only elementary methods from algebraic geometry. The main point is that, given a non-isotrivial and relatively minimal family f : X \to B, where X is a surface and B is a curve, both smooth and projective, we show that the direct image of the relatively canonical sheaf has strictly positive degree.

Keywords

Cite

@article{arxiv.math/0103225,
  title  = {An algebraic proof of Iitaka's Conjecture C_{2,1}},
  author = {Markus Wessler},
  journal= {arXiv preprint arXiv:math/0103225},
  year   = {2007}
}

Comments

7 pages

R2 v1 2026-07-22T16:37:56.982Z