English

Generic algebras: rational parametrization and normal forms

Algebraic Geometry 2015-01-20 v2

Abstract

For every algebraically closed field k\boldsymbol k of characteristic different from 22, we prove the following: (1) Generic finite dimensional (not necessarily associative) k\boldsymbol k-algebras of a fixed dimension, considered up to isomorphism, are parametrized by the values of a tuple of algebraically independent over k\boldsymbol k rational functions in the structure constants. (2) There exists an "algebraic normal form", to which the set of structure constants of every such algebra can be uniquely transformed by means of passing to its new basis, namely: there are two finite systems of nonconstant polynomials on the space of structure constants, {fi}iI\{f_i\}_{i\in I} and {bj}jJ\{b_j\}_{j\in J}, such that the ideal generated by the set {fi}iI\{f_i\}_{i\in I} is prime and, for every tuple cc of structure constants satisfying the property bj(c)0b_j(c)\neq 0 for all jJj\in J, there exists a unique new basis of this algebra in which the tuple cc' of its structure constants satisfies the property fi(c)=0f_i(c')=0 for all iIi\in I.

Keywords

Cite

@article{arxiv.1411.6570,
  title  = {Generic algebras: rational parametrization and normal forms},
  author = {Vladimir L. Popov},
  journal= {arXiv preprint arXiv:1411.6570},
  year   = {2015}
}

Comments

20 pages. Added details on separability in the proof of Theorems 2 and 5

R2 v1 2026-06-22T07:10:21.060Z