Kappa

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Variant kappa

Look up Κ, κ in Wiktionary, the free dictionary.

Greek alphabet
Αα Alpha	Νν Nu
Ββ Beta	Ξξ Xi
Γγ Gamma	Οο Omicron
Δδ Delta	Ππ Pi
Εε Epsilon	Ρρ Rho
Ζζ Zeta	Σσς Sigma
Ηη Eta	Ττ Tau
Θθ Theta	Υυ Upsilon
Ιι Iota	Φφ Phi
Κκ Kappa	Χχ Chi
Λλ Lambda	Ψψ Psi
Μμ Mu	Ωω Omega
Obsolete letters
Digamma	Qoppa
San	Sampi
Other characters
Stigma	Sho
Heta
Greek diacritics

Kappa (uppercase Κ, lowercase κ or ϰ; Greek: Κάππα) is the 10th letter of the Greek alphabet, used to represent the voiceless velar stop, or "k", sound in Ancient and Modern Greek. In the system of Greek numerals it has a value of 20. It was derived from the Phoenician letter Kaph. Letters that arose from kappa include the Roman K and Cyrillic К.

Greek proper names and placenames containing kappa are often written in English with "c" due to contemporary rendering into the Latin alphabet by ancient Romans. However, modern transliteration of the Greek language invariably use the letter "k". Compare Κυνοσκεφαλαι, Cynoscephalae (ancient placename); κυνος κεφαλαι, kunos kephalai (phrase), meaning "dog's heads".

Greek word καί written with a handwritten variant of kappa, from the Byzantine period

In mathematics, the kappa curve is named after this letter; the tangents of this curve were first calculated by Barrow (17th Century).

[edit] Symbol

In graph theory, the connectivity of a graph is given by κ.

In differential geometry, the curvature of a curve is given by κ.

In physics, the torsional constant of an oscillator is given by κ.

In chemistry, the compressibility of a compound is given by κ.

In physics, the dielectric constant of a capacitor is also given by κ.

In physics, the Einstein constant of gravitation

In psychology and psychiatry, kappa represents a measure of diagnostic reliability.

In biology, kappa and kappa prime are important nucleotide motifs for a tertiary interaction of group II introns.

In biology, kappa designates a subtype of an antibody component.

In pharmacology, kappa represents a type of opioid receptors.

Kappa statistics such as Cohen's kappa and Fleiss' kappa are methods for calculating interannotator agreement.

Upper-case letter Κ is used as a symbol for:

• In textual criticism, the Byzantine text-type (from Κοινη, Koine, the common text).