Λ

Lambda in a capital letter Etymologicum Magnum (1499).

Lambda (uppercase Λ, lowercase λ; Ancient Greek call λά(μ) βδα lá(m)bda /lá(m)b.da/, in modern Greek λάμ(β)δα lám(v)da /ˈlav.ða/ ) is the eleventh letter of the Greek alphabet. Ancient grammarians and playwrights give evidence of the pronunciation as [laːbdaː] (λάβδα) in classical Greek times; in modern Greek, the name of the lyrics is λάμδα.

In the Greek numeral system it has a value of 30 (Λʹ).

History

Epigraphic variants

In archaic epigraphic sources the following variants appear:

Use

The letter lambda is used as a symbol to represent:

• In physics and in other fields, the wavelength). It also designates the linear density value of load and the radioactive constant of an isotope.
• In cosmology, "cost" (capital call) is the symbol for the cosmological constant, a term introduced by Albert Einstein in the dynamic equations of his mathematical model of static Universe to characterize the accelerated expansion of the Universe.
• Thermodynamics represent the thermal conductivity coefficient of materials.
• It is also used in physics to designate a type of barion, the barion lambda.
• In biology designates the fago lambda virus (Enterobacteria fago λ)used in DNA replication.
• In geography and geodesy it is used to represent the meridian or length and its respective value.
• In medicine, lambda is the craniometric point located in the intersection of the sagital suture and lambdoid suture.
• In virology, in the context of the COVID-19 pandemic, the World Health Organization (WHO) designated as a variant of interest to lambda, a mutation of SARS-CoV-2, virus that produces COVID-19 disease, found in December 2020 in Peru.

The lambda sign represents amniotic sacs with a chorion between the membranes and is pathognomonic of dichorionicity in twin pregnancies.

• In a chemical reaction it indicates that a catalyst is needed in the reaction.
• In inorganic chemistry indicates that an apron of a coordination compound rotates the plane of polarized light to the left.
• In lambda calculation and by extension in some programming languages, the notation used to define functions whose result is part of another function.
• In the theory of automatons, it represents the "empty" chain within a word, for example the word "aaaλbb" would, simplifying, the word "aaabb".
• The initial letter of Lacedemonia in Greek, the name of the city-state of which Esparta was the nucleus. The capital letter lambda appeared printed on the shields of the Spartan counterparts.
• Lambda (cohete) was a family of Japanese rockets.
• In theory of probability and statistics, it is used as a parameter of the distribution of Poisson.
• In Volvo cars, it represents an error in engine, gasoline or car startup systems.
• In general mechanics it is used as coefficient of a mixture between fuel and comburent being λ=1 the stokyometric mixture.
• In mathematics it usually designates an angle, a plane, etc.
• In linear algebra usually designate the parametric equation parameter parameter of a straight line and its own values.
• Microeconomy is used to represent the Lagrangian multiplier, which can be applied in maximizing the consumer's utility or in minimizing total spending.
• Fractal image analysis is used to represent lacunarity.
• In the Greek numeration system it has a value of 30 (λ).
• The secularist movement in Europe uses it as a symbol.
• It is used to represent the famous video game of Valve, Half Life, in addition to being the name of a scientific installation of the first game.
• The videogame villain Tales of Graces is called Lambda and in its final form adopts the name of Lambda Angelus.
• One of the characters in the video game series BlazBlue She's an android girl named Lambda-11.
• It was chosen to symbolize the homosexual liberation campaign of the Homosexual Activists Alliance and is part of LGBT symbolism.
• Aphex Twin Logo

Unicode

Unicode uses the name "lamda" for character names instead of "lambda" due to "preferences expressed by the Greek National Corps".

• Greek and Coptic

• Maths