Nu (letter) explained

Nu (; uppercase Ν, lowercase ν; el|vι ni in Greek, Modern (1453-); pronounced as /ni/) is the thirteenth letter of the Greek alphabet, representing the voiced alveolar nasal in Greek, Modern (1453-); pronounced as /n/. In the system of Greek numerals it has a value of 50. It is derived from the Phoenician nun . Its Latin equivalent is N, though the lowercase (

) resembles the Roman lowercase v.

The name of the letter is written Greek, Ancient (to 1453);: νῦ in Ancient Greek and traditional Modern Greek polytonic orthography, while in Modern Greek it is written Greek, Modern (1453-);: νι pronounced as /[ni]/.

Letters that arose from nu include Roman N and Cyrillic script En.

Symbology

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^[1] 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.^[2]

• • (in TeX)

These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style:

See also

• Movable nu

Notes and References

1. See e.g. Planck's formula
2. Unicode Code Charts: Greek and Coptic (Range: 0370-03FF)