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Research draft

algebraic number

vr.tr.algebraic-number · XCT.QTY

Let an agent handle algebraic numbers by definition, minimal polynomial, degree and related structures in number theory.

Thing Registry Cross-cutting context

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent handle algebraic numbers by definition, minimal polynomial, degree and related structures in number theory.

A complex number that is a root of a non-zero polynomial with rational (equivalently integer) coefficients, such as square roots of integers and roots of unity; numbers that are not algebraic, like pi and e, are transcendental.

What it is for: Number theory, algebra and exact computation.

It can be find the minimal polynomial of a number; determine degree; distinguish algebraic and transcendental numbers; work with algebraic integers.

Distinguishing features

Countable set

Closed under arithmetic operations

Includes all rationals

Algebraic integers form a ring

What it looks like

Numbers expressed with radicals or as polynomial roots.

How it is recognised

Roots of integer polynomials

Degree equals minimal polynomial degree

Pi and e are transcendental

Related models

is a kind of - category

complex number

is contrasted with - complement

transcendental number

is studied in - field

algebraic number theory

forms - structure

number field

In practice

Families and kinds

rational numbers

quadratic irrationals

algebraic integers

roots of unity

Perron and Pisot numbers

Standards and regulation

ISO 80000-2 notation

Failure modes and hazards

Assuming irrational means transcendental

Numerical approximation errors

Also called

ideal numbersquare root of natural numbersalgebraic integerPerron number

Where this came from

wikidata · CC0 1.0

Also registered as vr.tr.algebraic-number

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Definition Is it algebraic.

Polynomials decide.

Test

Polynomial.

Test

Algebraicity.

  1. Is this number a root of a polynomial with integer coefficients? boundary
  2. Which polynomial? definition

Transcendental

Contrast.

Transcendental

Transcendence.

  1. Is the number known to be transcendental? provenance
  2. Or is its status open? boundary
Structure Degree.

Degree measures complexity.

Minimal polynomial

Degree.

Minimal polynomial

Minimal polynomial.

  1. What is its minimal polynomial and degree? measurement
  2. What are its conjugates? definition

Algebraic integers

Monic polynomials.

Algebraic integers

Algebraic integers.

  1. Is it an algebraic integer? boundary
  2. In which ring? definition
Computation Exact arithmetic.

Computers can handle them exactly.

Exact

Computer algebra.

Exact

Exact computation.

  1. How can it be represented exactly in software? action
  2. Which system supports it? provenance

Approximation

Numerics.

Approximation

Approximation.

  1. How accurate is the numerical approximation? measurement
  2. Could rounding mislead? boundary
Theory Number fields.

Algebraic numbers build fields.

Fields

Number fields.

Fields

Number fields.

  1. Which number field does it generate? definition
  2. What is its degree? measurement

History

Development.

History

History.

  1. How did the theory develop, including ideal numbers? provenance
  2. Which mathematicians contributed? provenance

What the second pass must settle

  • Should algebraic integers be a separate entry?
  • How should computer algebra be linked?
  • How should number fields be linked?