Omega (Greek letter)

Omega (uppercase Ω, lowercase ω) is the 24th and last letter of the Greek alphabet. In the Greek numeric system, it has a value of 800. Pronounced [ɔ:] or 'aw' as in 'raw'.

Symbol uppercase Ω

Astronomy

• density of the universe, also referred to as the cosmological density parameter. with components of mass density, Ω_M, and vacuum energy density, Ω_L.

Chemistry

• designation for the last carbon on the chain in a fatty acid

Electricity

• Ohm: SI unit of electrical resistance
• Siemens (unit), abbreviated S, is the reciprocal of the ohm.

Mathematics

• Omega constant (Lambert’s W function)
• Chaitin’s constant: the probability that a randomly selected valid program string is interpreted by a halting

term

• Calculus: a 2-D region
• A theoretical measure of the execution of an algorithm, (e.g. required time or memory) given the problem size n (e.g. the number of items).
• Stochastic process

Meteorology

• Used to designate vertical motion in the atmosphere

Statistics

• Sample space
• Set of possible outcomes

Literary

• End or last thing in a series

Physics

• Solid angle or rate of precession in a gyroscope
• Omega baryons (particle physics)
• Negatively charged elementary particle with a mass 3270 times the mass of an electron.
• Omega minus b: a very short-lived unstable meson with mass 1532 times the mass of an electron (aka omega meson)

Symbol lowercase ω

Mathematics

• The set of all natural numbers

Physics

• Angular frequency