PreprintCC0arXiv
Degree of irrationality of a product of two elliptic curves
Abstract
In this short paper, we prove that, for any two complex elliptic curves E and F, the product E× F has degree of irrationality 3. The upper bound is obtained from compatible cyclic plane-cubic models of E and F: three diagonal bihomogeneous sections define a dominant rational map E× Fdashrightarrowℙ2 of degree 3. The lower bound follows by excluding dominant rational maps of degrees 1 and 2 from an abelian surface to ℙ2.
Related
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- Supersingular Elliptic Curves Without Inseparable Small Degree Endomorphisms
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- $2$-adic Representations of Elliptic Curves over ℚ2
BibTeX
@misc{lee2026degree,
title = {{Degree of irrationality of a product of two elliptic curves}},
author = {Yongnam Lee},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2608.22178},
eprint = {2608.22178},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.22178},
note = {CC0},
}
RIS
TY - UNPB
TI - Degree of irrationality of a product of two elliptic curves
AU - Yongnam Lee
PY - 2026
DA - 2026/09/07
PB - arXiv
DO - 10.48550/arxiv.2608.22178
UR - https://arxiv.org/abs/2608.22178
AB - In this short paper, we prove that, for any two complex elliptic curves E and F, the product E× F has degree of irrationality 3. The upper bound is obtained from compatible cyclic plane-cubic models of E and F: three diagonal bihomogeneous sections define a dominant rational map E× Fdashrightarrowℙ^2 of degree 3. The lower bound follows by excluding dominant rational maps of degrees 1 and 2 from an abelian surface to ℙ^2.
ER -