The map to the orbifold base need not be an orbifold map
Algebraic Geometry
2026-03-09 v1
Abstract
We give an explicit example of a fibration between smooth projective varieties whose "orbifold base" in the sense of Campana has the property that the induced morphism is not a morphism of C-pairs (i.e., it is not an "orbifold morphism"). We however also show that this cannot happen if is "neat" and is sufficiently well-behaved. Finally, we discuss the implications of this statement towards conjectures of Campana aiming to give algebro-geometric characterizations of those varieties which either admit a dense entire curve or a potentially dense set of integral points.
Keywords
Cite
@article{arxiv.2603.06083,
title = {The map to the orbifold base need not be an orbifold map},
author = {Finn Bartsch},
journal= {arXiv preprint arXiv:2603.06083},
year = {2026}
}
Comments
13 pages, comments welcome!