PreprintCC BY 4.0arXiv
Isogeny rigidity under algebraic group actions and finite translation orbits
Abstract
We study finite orbits generated by fibrewise translations on varieties carrying two abelian fibrations. Under natural dominance and generation hypotheses, non-isotriviality of the first family forces points with finite orbit to lie over proper closed subsets of both bases. This extends results of Corvaja, Tsimerman and Zannier to complex families of arbitrary, possibly different relative dimensions, including torsors. The proof combines relative Manin-Mumford with a general isogeny rigidity theorem for algebraic group actions.
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BibTeX
@misc{dolce2026isogeny,
title = {{Isogeny rigidity under algebraic group actions and finite translation orbits}},
author = {Paolo Dolce and Francesco Tropeano and Ekaterina Amerik},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.03606},
eprint = {2611.03606},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.03606},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Isogeny rigidity under algebraic group actions and finite translation orbits
AU - Paolo Dolce
AU - Francesco Tropeano
AU - Ekaterina Amerik
PY - 2026
DA - 2026/11/02
PB - arXiv
DO - 10.48550/arxiv.2611.03606
UR - https://arxiv.org/abs/2611.03606
AB - We study finite orbits generated by fibrewise translations on varieties carrying two abelian fibrations. Under natural dominance and generation hypotheses, non-isotriviality of the first family forces points with finite orbit to lie over proper closed subsets of both bases. This extends results of Corvaja, Tsimerman and Zannier to complex families of arbitrary, possibly different relative dimensions, including torsors. The proof combines relative Manin-Mumford with a general isogeny rigidity theorem for algebraic group actions.
ER -