Lambda

Greek alphabet
Α α Alpha	Β β Beta
Γ γ Gamma	Δ δ Delta
Ε ε Epsilon	Ζ ζ Zeta
Η η Eta	Θ θ Theta
Ι ι Iota	Κ κ Kappa
Λ λ Lambda	Μ μ Mu
Ν ν Nu	Ξ ξ Xi
Ο ο Omicron	Π π Pi
Ρ ρ Rho	Σ σ Sigma
Τ τ Tau	Υ υ Upsilon
Φ φ Phi	Χ χ Chi
Ψ ψ Psi	Ω ω Omega
obsolete letters
Ϝ ϝ Digamma	Ϻ ϻ San
Ϙ ϙ Qoppa	Ϡ ϡ Sampi

Lambda (upper case Λ, lower case λ) is the 11th letter of the Greek alphabet. In the system of Greek numerals it has a value of 30.

In art and photography, a lambda-print is a positive image, usually a photograph, executed on photographic (light-sensitive) paper using a dedicated laser printer (e. g. Océ LightJet), as opposed to a C-type or an inkjet print.

The upper-case letter Λ is used as a symbol for:

• The lambda particles in particle physics
• The set of logical axioms in the axiomatic method of logical deduction in first-order logic
• The cosmological constant

The lower-case letter λ is used as a symbol for:

• A unit of measure of volume (symbol λ) equal to one microlitre (1 μL) or one cubic millimetre (1 mm³)
• The wavelength of a wave in physics
• The radioactive decay constant
• The lambda phage virus in biology
• Eigenvalues in linear algebra
• Function expressions in lambda calculus and, by extension, some programming languages
  • The language Unlambda is a functional programming language based upon combinatory logic, a simplification of the lambda calculus that does not involve the lambda at all, hence the un- prefix.
• Gay pride (explanations for this usage vary) and as a gay signifier, such as the Lambda Literary Award
• The Half-Life computer game
• Excess air ratio in an internal combustion engine
• A Japanese rocket type, Lambda (rocket)
• A shuttle type in Star Wars, Lambda Shuttle.

See also: Lambda, Alpha (letter), Axiomatic method, Baryon, Beta (letter), Chi (Greek letter), Combinatory logic, Cosmological constant