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congruent number

vr.tr.congruent-number · thing-q325978

Let an agent explain congruent numbers and the congruent number problem, relay known results, Tunnell theorem and the link to elliptic curves from mathematical references, and distinguish congruent numbers from the unrelated notion of congruence.

Thing Registry Cross-cutting context XCT.QTY

Bundle → Layer → Finding → Questions Filled

4 bundles · 8 layers · 8 findings · 16 questions

Understand What a congruent number is.

Definition

Definition.

Definition

Definition.

  1. What is a congruent number, and why is 5 congruent but 1, 2 and 3 not? definition
  2. Is the question about congruent numbers or about congruence modulo n? boundary

Examples

Examples.

Examples

Examples.

  1. What are the small congruent numbers, and what rational triangles realise them? measurement
  2. Which entry fits rational right triangle? action
Theory Theory.

Elliptic

Elliptic curves.

Elliptic

Elliptic.

  1. How does n being congruent correspond to the elliptic curve y^2 = x^3 - n^2 x having positive rank? provenance
  2. Which references are standard? provenance

Tunnell

Tunnell theorem.

Tunnell

Tunnell.

  1. What does Tunnell theorem say, and why does it depend on the Birch and Swinnerton-Dyer conjecture? provenance
  2. Which entry fits Birch and Swinnerton-Dyer conjecture? action
Problem The open problem.

Status

Status.

Status

Status.

  1. What is known and unknown about classifying congruent numbers? provenance
  2. Which sources are cited? provenance

Computation

Computation.

Computation

Computation.

  1. How have large computations enumerated congruent numbers? provenance
  2. Which entry fits computational number theory? action
Context History.

History

History.

History

History.

  1. How did the problem arise in Arabic manuscripts and Fibonacci work, and how did Fermat show 1 is not congruent? provenance
  2. Which entry fits the history of number theory? action

Culture

Popular mathematics.

Culture

Culture.

  1. How is the congruent number problem presented in popular mathematics? provenance
  2. Which entry fits unsolved problems in mathematics? action

Classifiers Filled

Family
Thing Registry
Category
Cross-cutting context
Entry kind
thing
Plane
XCT
Domain
XCT.QTY

What it is Filled

A congruent number is a positive integer that is the area of a right triangle with rational side lengths, such as 5, 6, 7, 20, 21 and 24. The congruent number problem has roots in ancient Arabic and medieval mathematics and remains open in general. A positive integer n is congruent if and only if the elliptic curve y^2 = x^3 - n^2 x has positive rank over the rational numbers, an unconditional equivalence. For squarefree positive integers, Tunnell's theorem gives an unconditional necessary criterion for congruence; sufficiency of that criterion depends on the Birch and Swinnerton-Dyer conjecture.

Why it exists Filled

Let an agent explain congruent numbers and the congruent number problem, relay known results, Tunnell theorem and the link to elliptic curves from mathematical references, and distinguish congruent numbers from the unrelated notion of congruence.

Distinguishing features Filled

  • Rational right triangle area
  • Ancient origin
  • Elliptic curve connection
  • Open problem

What robots and AI may and may not do Filled

Must not

  • Present a result that depends on an unproved conjecture as unconditional.
  • Claim a number is or is not congruent without a check or a source.
  • Misattribute historical or modern results to the wrong mathematicians.

Only with a human decision

  • Announcing a claimed proof of an open problem in this area.

May

  • Test, list and explain congruent numbers with stated methods and sources.
  • Make clear which results depend on unproved conjectures.

Moral aspects Filled

  • Credit for results in number theory belongs to those who proved them.
  • False claims about open problems mislead students and waste reviewers' time.

Who is affected

  • Mathematicians
  • Students

Owners Filled

Steward

Nobody owns the concept; it is held in common.

Links to other meta-models Filled

parent

  • Q16317911 - registry parent class

related

  • positive integer - in registry terms
  • Tunnell theorem - conditionally
  • elliptic curve - y^2 = x^3 - n^2 x
  • OEIS - as A003273

What else AI and robots need to interact with it Filled

Identity and identifiers required Filled

  • Vercy registry: vr.tr.congruent-number
  • Wikidata: Q325978 (https://www.wikidata.org/wiki/Q325978)
  • OEIS: A003273 congruent numbers

Direct properties not applicable Not applicable

  • smallest congruent number: 5 value - triangle 3/2, 20/3, 41/6
  • congruent numbers below 100: 37 count - OEIS A003273
  • Tunnell theorem: 1983 year

Plane XCT: no invented physical properties.

Recognition optional Filled

  • Area of a rational right triangle
  • Congruent numbers 5, 6, 7, 13, 14, 15, 20, 21, 22, 23, 24
  • Congruence modulo n is a different concept; Pythagorean triples give integer-sided triangles
  • Not a visible object; integers and rational triangles.

Capabilities and actions required Filled

  • explain the definition
  • relay known results
  • describe the elliptic curve link
  • distinguish from congruence

Hazards and failure modes required Filled

  • Confusing with modular congruence
  • Overstating what is proved unconditionally
  • Missing the squarefree reduction

Standards and interfaces required Filled

  • No regulation; standard mathematical definitions

Context of use required Filled

  • Not applicable; a mathematical concept.
  • congruent numbers
  • non-congruent numbers such as 1, 2, 3 and 4
  • squarefree congruent numbers as the essential cases
  • residue class results such as numbers congruent to 5, 6 or 7 mod 8 under BSD

Sources Filled

  1. Wikidata item Q325978: congruent number - identity and sense of the item
  2. Wikipedia: Congruent number - general description of the item

Open questions

  • Should the congruent number problem be a separate entry?
  • How should mathematical references be linked?
  • How should computational results such as the 2009 trillion-number computation be recorded?

Machine files

Provenance

thing registry research (pass 2) · unreviewed

Built from: models/things/publications/thing-q325978/spec.json