Theorem

Jordan Curve Theorem

Topology

Every simple closed curve in the plane divides the plane into exactly two regions, an interior and an exterior, and the curve is the common boundary of both. Named for Camille Jordan, its statement is visually obvious but its rigorous proof is surprisingly delicate.

Facts
Disputed
Proof Year
1887 1
Jordan published a claimed proof in 1887; for decades many mathematicians considered that proof flawed and credited Oswald Veblen with the first rigorous proof, but this assessment has since been challenged by Thomas Hales and others, so which proof was genuinely first and correct is not settled among historians of mathematics.
Statement
Every simple closed curve in the plane divides the plane into exactly two regions, a bounded interior and an unbounded exterior, and any continuous path from a point in one region to a point in the other must cross the curve. 1
Classification
Statement Form
Characterization Theorem 1
Jordan Curve Theorem
Filter Results1 entry
Connections

Has Statement Form

In Branch

Principal Result Of

Source MacTutor History of Mathematics: Camille Jordan - MacTutor biography
Source Oswald Veblen (Wikipedia)

Proved By

Sources
1. Jordan Curve Theorem (Wikipedia)
Wikimedia Foundation
  • Lead section
    For decades, mathematicians generally thought that this proof was flawed and that the first rigorous proof was carried out by Oswald Veblen; however, this notion has been overturned by Thomas C. Hales and others.
  • In Group: Geometric and Differential Topology, Lead paragraph
    In topology, a discipline within mathematics, the Jordan curve theorem (JCT), formulated by Camille Jordan in 1887, asserts that every simple closed curve in the plane (known as a Jordan curve) divides the plane into two regions: the interior, bounded by the curve, and an unbounded exterior, containing all of the nearby and faraway exterior points.
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MacTutor History of Mathematics: Camille Jordan - MacTutor biography
MacTutor History of MathematicsPrincipal Result Of: Camille Jordan, Biography text
Quote, Principal Result Of: Camille Jordan, Biography text
Jordan is best remembered today among analysts and topologists for his proof that a simply closed curve divides a plane into exactly two regions, now called the Jordan curve theorem .
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Oswald Veblen (Wikipedia)
Principal Result Of: Oswald Veblen, Lead, principal result
Quote, Principal Result Of: Oswald Veblen, Lead, principal result
He proved the Jordan curve theorem in 1905
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