Infinitesimal commutative unipotent group schemes with one-dimensional Lie algebra
Abstract
Abstract We prove that over an algebraically closed field of characteristic $$p>0$$ p > 0 there are exactly, up to isomorphism, n infinitesimal commutative unipotent k -group schemes of order $$p^n$$ p n with one-dimensional Lie algebra, and we explicitly describe them. We consequently obtain an explicit description of all infinitesimal subgroup schemes of any supersingular elliptic curve over an algebraically closed field, recovering all their $$p^n$$ p n -torsions as well. Finally, we use these results to answer a question of Brion on rational actions of infinitesimal commutative unipotent group schemes on curves.
Fields of Study & Subjects
Advanced Algebra and Geometry
Advanced Topics in Algebra
Algebraic structures and combinatorial models
Publication details
- Journal / source
- Mathematische Zeitschrift
- Publisher
- Springer Science and Business Media LLC
- Volume
- 312
- Issue
- 2
- Publication date
- 20 January 2026
- Language
- EN