Lambda

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.