A surface with representable $\text{CH}_{0}$-group but no universal zero-cycle
Abstract
We introduce a new obstruction to the existence of a universal -cycle on a smooth projective complex variety. As an application, we construct a smooth projective complex surface whose Chow group of -cycles is representable but which does not admit a universal -cycle. This provides a two-dimensional analogue of Voisin's recent threefold counterexample to a question of Colliot-Th\'el\`ene. As a further consequence, we exhibit the first example of a smooth projective threefold of Kodaira dimension zero carrying a non-torsion Hodge class of degree that is not algebraic. The construction relies on the geometry of bielliptic surfaces of type 2.
Cite
@article{arxiv.2602.13435,
title = {A surface with representable $\text{CH}_{0}$-group but no universal zero-cycle},
author = {Theodosis Alexandrou},
journal= {arXiv preprint arXiv:2602.13435},
year = {2026}
}
Comments
30 pages, minor revisions; several assumptions have been relaxed, examples have been added and the exposition has been improved