Nu (; uppercase Ν, lowercase ν; , ) is the thirteenth letter of the Greek alphabet, representing the voiced alveolar nasal . In the system of Greek numerals it has a value of 50. It is derived from the Phoenician letter nun (𐤍). Its Latin equivalent is N, though the lowercase (<math>\nu</math>) resembles the Roman lowercase v.
The name of the letter is (, ) in Ancient Greek, while in Modern Greek it is (, ).
Letters that arose from nu include N in the Latin script and En (Н) in Cyrillic.
Symbology
thumb|upright=.95|Bust of [[Nikos Kazantzakis with the traditional Greek nu]]
The lower-case letter is used as a symbol in many academic fields. Uppercase nu is not used, because it appears identical to Latin N.
- Mathematics:
- Degrees of freedom in statistics.
- The greatest fixed point of a function, as commonly used in the μ-calculus.
- Free names of a process, as used in the π-calculus.
- One of the Greeks in mathematical finance, known as "vega".
- The reciprocal of 1 plus the interest rate in finance.
- The -adic valuation or -adic order of a number.
- Physics:
- Kinematic viscosity in fluid mechanics.
- The frequency of a wave in physics and other fields; sometimes also spatial frequency; wavenumber
- The specific volume in thermodynamics.
- Poisson's ratio, the ratio of strains perpendicular with and parallel with an applied force.
- Any of three kinds of neutrino in particle physics.
- The number of neutrons released per fission of an atom in nuclear physics.
- Molecular vibrational mode, where is the number of the vibration (a label).
- The true anomaly, an angular parameter that defines the position of a body moving along an orbit (see orbital elements).
- Biology:
- A DNA polymerase found in higher eukaryotes and implicated in translesion synthesis.
- Chemistry:
- The stoichiometric coefficient.
- Psychology:
- The maximum conditioning possible for an unconditioned stimulus in the Rescorla-Wagner model.
Unicode
Encodings of Greek Nu and Coptic Ni.
- ( in TeX)
See also
- Movable nu