Statements (23)
Predicate | Object |
---|---|
gptkbp:instanceOf |
3-manifold
homology sphere |
gptkbp:alsoKnownAs |
gptkb:Poincaré_homology_sphere
|
gptkbp:BrieskornParameters |
(2,3,5)
|
gptkbp:canBe |
gluing opposite faces of a dodecahedron after a 1/10 turn
|
gptkbp:describedBy |
gptkb:Brieskorn_sphere
gptkb:Seifert_fiber_space dodecahedral space |
gptkbp:directionA |
orientable
|
gptkbp:fundamentalGroup |
gptkb:binary_icosahedral_group
|
gptkbp:fundamentalGroupOrder |
120
|
gptkbp:hasFirstHomologyGroup |
trivial
|
gptkbp:hasHeegaardGenus |
2
|
gptkbp:hasSecondHomologyGroup |
trivial
|
gptkbp:hasThirdHomologyGroup |
Z
|
gptkbp:heldBy |
first discovered example of a homology sphere not homeomorphic to the 3-sphere
|
https://www.w3.org/2000/01/rdf-schema#label |
Σ(2,3,5) (Poincaré sphere)
|
gptkbp:isBrieskornSphere |
yes
|
gptkbp:isSolutionTo |
Poincaré conjecture (as a counterexample to naive formulation)
|
gptkbp:namedAfter |
gptkb:Henri_Poincaré
|
gptkbp:universalCover |
gptkb:3-sphere
|
gptkbp:bfsParent |
gptkb:Brieskorn_sphere
|
gptkbp:bfsLayer |
7
|