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Theorem

Freedman's Theorem

Topology

Freedman's Theorem classifies simply connected, compact, four-dimensional topological manifolds up to homeomorphism by a small set of algebraic invariants, chiefly the manifold's intersection form together, in the case of an odd form, with an extra invariant distinguishing two homeomorphism types for the same form. Named for Michael Freedman, who proved it in 1982, it settled the topological, though not the smooth, case of the four-dimensional Poincare Conjecture, showing that a simply connected topological four-manifold with the intersection form of the ordinary four-sphere must be homeomorphic to that sphere.

Facts
Statement
Every symmetric unimodular bilinear form is the intersection form of a simply connected oriented closed topological 4 manifold. 2
Proof Year
1982 2
Classification
Statement Form
Classification Theorem 1
Connections

Has Statement Form

In Branch

Source Wikipedia: Freedman classification

Proved By

Source Wikipedia: Freedman classification
Sources
1. Wikipedia: Freedman classification
Wikipedia
  • Lead section, statement-form reference
    Concretely, it gives a full classification of all simply connected oriented closed topological 4-manifolds up to orientation-preserving homeomorphism by their intersection form and their Kirby-Siebenmann invariant.
  • In Branch: Topology, Lead sentence
    In topology in mathematics, Freedman's classification (or Freedman's theorem) is a central result about four-dimensional topologic
  • Proved By: Michael Freedman, Lead
    Freedman's classification is named after Michael Freedman, who published it in 1982 and who was awarded the Fields Medal for it in 1986.
  • In Group: Geometric and Differential Topology, Lead paragraph
    In topology in mathematics, Freedman's classification (or Freedman's theorem) is a central result about four-dimensional topological manifolds (short 4-manifolds).
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2. Freedman's theorem (Wikipedia)
  • Statement section
    Every symmetric unimodular bilinear form is the intersection form of a simply connected oriented closed topological 4-manifold.
  • Lead section
    Freedman's classification is named after Michael Freedman, who published it in 1982 and who was awarded the Fields Medal for it in 1986.
View the Source
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