Phrase guide

Riemann sphere

noun · 2 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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1

noun

Meaning 1

The complex numbers extended with the number ∞; the complex plane (representation of the complex numbers as a Euclidean plane) extended with a single idealised point at infinity and consequently homeomorphic to a sphere in 3-dimensional Euclidean space.

Definition source: English Wiktionary via Wiktextract

Topics: complex-analysis, mathematics, sciences, topology

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

The 2-sphere embedded in Euclidean three-dimensional space and often represented as a unit sphere, regarded as a homeomorphic representation of the extended complex plane and thus the extended complex numbers.

Definition source: English Wiktionary via Wiktextract

Topics: complex-analysis, mathematics, sciences, topology

Examples

  • 1967 [Prentice-Hall], Richard A. Silverman, Introductory Complex Analysis, Dover, 1972, page 22, Every circle γ on the Riemann sphere Σ which does not go through a given point P^*∈Σ divides Σ into two parts, such that one part contains P^* and the other does not.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

History

Etymology

Named after German mathematician Bernhard Riemann.

Across languages

Translations

7 source translations are retained for this English entry.

  • Dutch: Riemann-sfeer — complex plane with a point at infinity
  • Italian: sfera di Riemann — complex plane with a point at infinity
  • Polish: sfera Riemanna — complex plane with a point at infinity
  • Russian: сфе́ра Ри́мана (sféra Rímana) — complex plane with a point at infinity
  • Italian: sfera di Riemann — Euclidean sphere as a representation
  • Polish: sfera Riemanna — Euclidean sphere as a representation
  • Russian: сфе́ра Ри́мана (sféra Rímana) — Euclidean sphere as a representation