English

The Conjugates of Algebraic Schemes

Algebraic Geometry 2007-12-17 v4

Abstract

Fixed an algebraic scheme YY. We suggest a definition for the conjugate of an algebraic scheme XX over YY in an evident manner; then XX is said to be Galois closed over YY if XX has a unique conjugate over YY. Now let XX and YY both be integral and let XX be Galois closed over YY by a surjective morphism ϕ\phi of finite type. Then ϕ(k(Y))\phi^{\sharp}(k(Y)) is a subfield of k(X)k(X) by ϕ\phi. The main theorem of this paper says that k(X)/ϕ(k(Y))k(X) /\phi^{\sharp}(k(Y)) is a Galois extension and the Galois group Gal(k(X)/ϕ(k(Y)))Gal(k(X)/\phi^{\sharp}(k(Y))) is isomorphic to the group of kk-automorphisms of XX over YY.

Keywords

Cite

@article{arxiv.math/0702493,
  title  = {The Conjugates of Algebraic Schemes},
  author = {Feng-Wen An},
  journal= {arXiv preprint arXiv:math/0702493},
  year   = {2007}
}

Comments

A reduced and refined version. 26 Pages

R2 v1 2026-07-22T17:51:13.786Z