English

Modified Derksen invariant

Algebraic Geometry 2024-12-10 v2

Abstract

Modified Derksen invariant HD*(X) of an affine variety X is a subalgebra in K[X] generated by kernels of all locally nilpotent derivations of K[X] with slices. If there is a locally nilpotent derivation of K[X] with a slice then X is a product of Y and a line, where Y is an affine variety. We prove that there are three possibilities: A) HD*(X) = K[X]; B) HD*(X) is a proper infintely generated subalgebra; C) HD*(X) = \BK[Y]. We give examples for each case, and also provide sufficient conditions for the variety Y so that the variety X belongs to one of the type.

Keywords

Cite

@article{arxiv.2312.08421,
  title  = {Modified Derksen invariant},
  author = {Ilya Boldyrev and Sergey Gaifullin and Anton Shafarevich},
  journal= {arXiv preprint arXiv:2312.08421},
  year   = {2024}
}
R2 v1 2026-06-28T13:50:08.635Z