Nu (letter)

For other uses, see Nu (disambiguation).

Not to be confused with Mu (letter), N, or En (Cyrillic).

Nu (/ˈnjuː/; uppercase Ν, lowercase ν; Greek: vι ni [ni]) is the thirteenth letter of the Greek alphabet, representing the voiced alveolar nasal IPA: [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 (${\displaystyle \nu }$) resembles the Roman lowercase v.

The name of the letter is written νῦ in Ancient Greek and traditional Modern Greek polytonic orthography, while in Modern Greek it is written νι [ni].

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

Symbology

Bust of Nikos Kazantzakis with the traditional Greek nu

The lower-case letter ν 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 p-adic valuation or p-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, ν_x where x 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.

Character encodings

Greek Nu/Coptic Ni

Encodings of Greek Nu and Coptic Ni.^[2]

Character information

Preview	Ν		ν		Ⲛ		ⲛ
Unicode name	GREEK CAPITAL LETTER NU		GREEK SMALL LETTER NU		COPTIC CAPITAL LETTER NI		COPTIC SMALL LETTER NI
Encodings	decimal	hex	dec	hex	dec	hex	dec	hex
Unicode	925	U+039D	957	U+03BD	11418	U+2C9A	11419	U+2C9B
UTF-8	206 157	CE 9D	206 189	CE BD	226 178 154	E2 B2 9A	226 178 155	E2 B2 9B
Numeric character reference	Ν	Ν	ν	ν	Ⲛ	Ⲛ	ⲛ	ⲛ
Named character reference	Ν		ν
DOS Greek	140	8C	164	A4
DOS Greek-2	181	B5	231	E7
Windows 1253	205	CD	237	ED
TeX			\nu

BBX Mathematical Nu

Character information

Preview	𝚴		𝛎		𝛮		𝜈		𝜨		𝝂
Unicode name	MATHEMATICAL BOLD CAPITAL NU		MATHEMATICAL BOLD SMALL NU		MATHEMATICAL ITALIC CAPITAL NU		MATHEMATICAL ITALIC SMALL NU		MATHEMATICAL BOLD ITALIC CAPITAL NU		MATHEMATICAL BOLD ITALIC SMALL NU
Encodings	decimal	hex	dec	hex	dec	hex	dec	hex	dec	hex	dec	hex
Unicode	120500	U+1D6B4	120526	U+1D6CE	120558	U+1D6EE	120584	U+1D708	120616	U+1D728	120642	U+1D742
UTF-8	240 157 154 180	F0 9D 9A B4	240 157 155 142	F0 9D 9B 8E	240 157 155 174	F0 9D 9B AE	240 157 156 136	F0 9D 9C 88	240 157 156 168	F0 9D 9C A8	240 157 157 130	F0 9D 9D 82
UTF-16	55349 57012	D835 DEB4	55349 57038	D835 DECE	55349 57070	D835 DEEE	55349 57096	D835 DF08	55349 57128	D835 DF28	55349 57154	D835 DF42
Numeric character reference	𝚴	𝚴	𝛎	𝛎	𝛮	𝛮	𝜈	𝜈	𝜨	𝜨	𝝂	𝝂

Character information

Preview	𝝢		𝝼		𝞜		𝞶
Unicode name	MATHEMATICAL SANS-SERIF BOLD CAPITAL NU		MATHEMATICAL SANS-SERIF BOLD SMALL NU		MATHEMATICAL SANS-SERIF BOLD ITALIC CAPITAL NU		MATHEMATICAL SANS-SERIF BOLD ITALIC SMALL NU
Encodings	decimal	hex	dec	hex	dec	hex	dec	hex
Unicode	120674	U+1D762	120700	U+1D77C	120732	U+1D79C	120758	U+1D7B6
UTF-8	240 157 157 162	F0 9D 9D A2	240 157 157 188	F0 9D 9D BC	240 157 158 156	F0 9D 9E 9C	240 157 158 182	F0 9D 9E B6
UTF-16	55349 57186	D835 DF62	55349 57212	D835 DF7C	55349 57244	D835 DF9C	55349 57270	D835 DFB6
Numeric character reference	𝝢	𝝢	𝝼	𝝼	𝞜	𝞜	𝞶	𝞶

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

References

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