Ωω

OMEGA

ὦ μέγα · [ɔː]

The 24th letter of the Greek alphabet.

MATHEMATICS

  • Order notation: Ω(·) (asymptotic lower bound).
  • Set/constant in various contexts.

PROBABILITY

  • Sample space: Ω.
  • Events are subsets of Ω.

STATISTICS

  • Formal basis: (Ω, F, P).
  • Organizes events/random variables.

PRONUNCIATION

Ancient Greek
sound [ɔː]
Modern Greek
ωμέγα [oˈmeɣa] · sound [o]

IN FORMULAS

  • P(Ω) = 1Ω is the sample space: everything that can happen has probability 1.

HOW TO WRITE IT — click to copy

lowercase
uppercase

DON'T CONFUSE IT

  • ω w ϖ π ω is round, like two u's joined; the Latin w is angular; ϖ is the variant pi, with a bar on top.

Note: notations vary between books/fields; these are the most common usages.