Riemann sphere
E259767
Riemann surface
compact Riemann surface
complex manifold
complex projective line
extended complex plane
mathematical object
one-dimensional complex manifold
simply connected surface
The Riemann sphere is the complex plane plus a point at infinity, forming a one-dimensional complex manifold topologically equivalent to a sphere and used to study meromorphic functions and complex analysis.
All labels observed (3)
| Label | Occurrences |
|---|---|
| Riemann sphere canonical | 4 |
| \hat{\mathbb{C}} | 1 |
| complex projective line | 1 |
Statements (51)
| Predicate | Object |
|---|---|
| instanceOf |
Riemann surface
ⓘ
compact Riemann surface ⓘ complex manifold ⓘ complex projective line ⓘ extended complex plane ⓘ mathematical object ⓘ one-dimensional complex manifold ⓘ simply connected surface ⓘ |
| alsoKnownAs |
Riemann sphere
ⓘ
surface form:
complex projective line
extended complex plane ⓘ projective line over the complex numbers ⓘ |
| automorphismGroup |
Möbius transformations
ⓘ
fractional linear transformations ⓘ |
| automorphismGroupIsomorphicTo | PSL(2,\mathbb{C}) ⓘ |
| constructedBy | stereographic projection of complex plane onto sphere ⓘ |
| contains | complex plane ⓘ |
| coordinateModel | complex projective coordinates [z:1] and [1:0] ⓘ |
| curvature | constant positive curvature in standard metric ⓘ |
| definedAs | complex plane plus a point at infinity ⓘ |
| dimension | 1 complex dimension ⓘ |
| distinguishedPoint | infinity ⓘ |
| EulerCharacteristic | 2 ⓘ |
| fundamentalGroup | trivial group ⓘ |
| genus | 0 ⓘ |
| hasChart |
stereographic projection from north pole
ⓘ
stereographic projection from south pole ⓘ |
| hasPoint | point at infinity ⓘ |
| homotopyType | 2-sphere S^2 ⓘ |
| isCompact | true ⓘ |
| isConnected | true ⓘ |
| isOnePointCompactificationOf | complex plane ⓘ |
| isSimplyConnected | true ⓘ |
| namedAfter | Bernhard Riemann ⓘ |
| property |
every holomorphic function on it is constant
ⓘ
every meromorphic function on complex plane extends to holomorphic map to Riemann sphere ⓘ every rational function defines a holomorphic self-map ⓘ |
| realDimension | 2 ⓘ |
| roleIn |
classification of compact Riemann surfaces
ⓘ
model for one-point compactification of complex plane ⓘ |
| symbol |
Riemann sphere
self-linksurface differs
ⓘ
surface form:
\hat{\mathbb{C}}
\mathbb{C} \cup \{\infty\} ⓘ |
| topologicallyEquivalentTo |
2-sphere
ⓘ
unit sphere in \mathbb{R}^3 ⓘ |
| usedIn |
algebraic geometry
ⓘ
complex analysis ⓘ complex dynamics ⓘ conformal mapping theory ⓘ dynamical systems ⓘ geometric function theory ⓘ projective geometry ⓘ theory of meromorphic functions ⓘ |
Referenced by (6)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject surface form:
Riemann surface
this entity surface form:
complex projective line
this entity surface form:
\hat{\mathbb{C}}