Module

Geometric.lean

Nyll.SchemeTheory.PlaneCurves.Geometric
5 declarations indexed from sourceView source ↗

Field Arithmetic, Chapter 6: plane curves

This file starts the source-producing infrastructure for Section 6.1: scalar extension to an algebraic closure and the zero sets of multivariate polynomials.

Imports3
  • Mathlib.Algebra.MvPolynomial.Eval
  • Mathlib.Algebra.MvPolynomial.Nilpotent
  • Mathlib.FieldTheory.IsAlgClosed.AlgebraicClosure
Imported by2

Declarations

FieldArithmetic.Chapter06.mapToAlgebraicClosure

Extend the coefficients of a multivariate polynomial to an algebraic closure.

Source context 5 commands

Surrounding namespaces, section variables, and local commands at this declaration.

namespace FieldArithmetic
namespace Chapter06
open MvPolynomial
universe u v
variable {K : Type u} [Field K]
def mapToAlgebraicClosure {σ : Type*} (f : MvPolynomial σ K) :
    MvPolynomial σ (AlgebraicClosure K)
FieldArithmetic.Chapter06.IsAbsolutelyIrreducible

Absolute irreducibility, expressed over a fixed algebraic closure.

Source context 5 commands

Surrounding namespaces, section variables, and local commands at this declaration.

namespace FieldArithmetic
namespace Chapter06
open MvPolynomial
universe u v
variable {K : Type u} [Field K]
def IsAbsolutelyIrreducible {σ : Type*} (f : MvPolynomial σ K) : Prop
FieldArithmetic.Chapter06.IsAbsolutelyIrreducible.irreducible

An absolutely irreducible polynomial is already irreducible over its original coefficient field.

Source context 5 commands

Surrounding namespaces, section variables, and local commands at this declaration.

namespace FieldArithmetic
namespace Chapter06
open MvPolynomial
universe u v
variable {K : Type u} [Field K]
theorem IsAbsolutelyIrreducible.irreducible
    {σ : Type*} {f : MvPolynomial σ K}
    (hf : IsAbsolutelyIrreducible f) :
    Irreducible f
FieldArithmetic.Chapter06.affineZeroSet

The zero set of a multivariate polynomial after applying a coefficient map.

Source context 5 commands

Surrounding namespaces, section variables, and local commands at this declaration.

namespace FieldArithmetic
namespace Chapter06
open MvPolynomial
universe u v
variable {K : Type u} [Field K]
def affineZeroSet {σ : Type*} {R : Type u} {S : Type v}
    [CommSemiring R] [CommSemiring S] (φ : R →+* S) (f : MvPolynomial σ R) :
    Set (σ → S)
FieldArithmetic.Chapter06.geometricZeroSet

The geometric zero set of a polynomial over a fixed algebraic closure.

Source context 5 commands

Surrounding namespaces, section variables, and local commands at this declaration.

namespace FieldArithmetic
namespace Chapter06
open MvPolynomial
universe u v
variable {K : Type u} [Field K]
def geometricZeroSet {σ : Type*} (f : MvPolynomial σ K) :
    Set (σ → AlgebraicClosure K)