List of letters used in mathematics and science

This list is about the meanings of the letters used in mathematics and science. SI units are indicated in parentheses. For the Unicode block, see Mathematical Alphanumeric Symbols.
This list is incomplete; you can help by expanding it.

Some common conventions:


Latin

A — Ampere, area, a blood type, a spectral type, vector potential, Work

B — B meson, a blood type, boron, luminance, magnetic field, a spectral type

C — carbon, degrees Celsius, set of complex numbers, coulomb, molar heat capacity, the C programming language, specific heat capacity, Cunningham correction factor

D — deuterium, differential operator, electric displacement, D meson, density

E — electric field, energy, SI prefix exa–, expected value

F — degrees Fahrenheit, farad, fluorine, force, Helmholtz free energy, a spectral type

G — Einstein tensor, SI prefix giga–, Gibbs free energy, gravitational constant, Green's function, Momentum, a Spectral type

H — auxiliary magnetic field, enthalpy, Hamiltonian, Hankel function, Heaviside step function, Henry, Higgs boson, homology group, Hubble constant, hydrogen, set of quaternions, hat matrix

I — iodine, impulse, luminous intensity, moment of inertia, current

J — angular momentum, Bessel function of the first kind, current, joule

K — kaon, kelvin, potassium, sectional curvature, a spectral type

L — angular momentum, inductance (Henries), Lagrangian, litre, a spectral type

M — magnetization, mass, SI prefix mega–, a spectral type, torque

N — Avogadro's number, Bessel function of the second kind, set of natural numbers, newton, nitrogen, normal distribution, normal vector

O — big O notation, a blood type, oxygen, a spectral type

P — Legendre polynomial, luminous flux, phosphorus, polarization, power, pressure, probability, projection

Q — electric charge, quantity of heat, set of rational numbers, flow rate

R — curvature tensor, electrical resistance, radius, set of real numbers

S — area, entropy, siemens, sphere, spin operator, sulfur, symmetric group

T — a spectral type, temperature, tesla, tritium

U — potential energy, uranium, unitary operator

V — potential energy, vanadium, volt, voltage, volume

W — energy, Lambert's W function, tungsten, watt, W boson, Work, work function, Wiener process

X — random variable, abscissa

Y — Bessel function of the second kind, SI prefix yotta–, yttrium, ordinate, luminance

Z — atomic number, impedance, set of integers, partition function (statistical mechanics), partition function (quantum field theory), Z boson, SI prefix zetta–, altitude

a — SI prefix atto–, acceleration, reflectance

b — Bottom quark

c — SI prefix centi–, Charm quark, speed of light, speed of sound

d — SI prefix deci–, distance, Down quark, infinitesimal increment, differential operator, density

e — Napier's constant, electron, positron, electric charge

f — SI prefix femto–, frequency

g — gram, gravitational acceleration, gravitational field, distance metric of spacetime

h — height, hour, Planck's constant, spherical Hankel function

i — imaginary complex unit, imaginary quaternion unit, unit vector, current, row index

j — electric current and current density, radiant intensity, spherical Bessel function of the first kind, unit vector, column index, imaginary complex unit, imaginary quaternion unit

k — Boltzmann constant, imaginary quaternion unit, SI prefix kilo–, wave vector, unit vector

l — length, litre, mean free path

m — magnitude, mass, SI prefix milli–, metre, minute

n — SI prefix nano–, neutron, refractive index, spherical Bessel function of the second kind

o — small o notation

p — electric dipole moment, momentum, SI prefix pico-, proton, point of a space, sound pressure

q — electric charge, generalized coordinate

r — position (vector), radial polar coordinate, radius

s — second, Strange quark

t — period, time, Top quark

u — Up quark

v — velocity (m/s)

w — velocity (m/s)

x — abscissa, real-valued argument, variable to be determined, vector,

y — ordinate, SI prefix yocto-, pixel row index

z — complex variable, altitude, SI prefix zepto-

Greek

Β — Beta function

Γ — Angular momentum, Gamma function, Christoffel symbols

Δ — A macroscopic change in the value of a variable, Laplace operator, Delta particle

Θ — Heaviside step function

Λ — Iwasawa algebra, Lorentz transformation, Lambda Hyperon

Ξ — Cascade Hyperon

Π — Product

Σ — Sum, Surface, Sigma Hyperon

Φ — Alternative symbol for Quantum mechanical wavefunction

Ψ — Quantum mechanical wavefunction

Ω — Chaitin's constant, Ohm, Solid angle, Omega Hyperon

α — Alpha particle, Fine structure constant, Angular acceleration

β — Beta particle, Inverse temperature

γ — Euler-Mascheroni constant, Gamma-ray (Photon), Photon, Relativistic gamma factor

δ — Dirac delta function, Infinitesimal quantity, Kronecker delta

ε — Infinitesimal quantity, Permittivity

ζ — Damping Ratio, Riemann zeta function

η — Distance metric of flat spacetime, Efficiency, Dynamic viscosity, η-meson

θ — Angle, Angular polar coordinate, Temperature

ι -

κ — Gravitational constant

λ — Half-life, Lagrangian multiplicator, Lambda expression, Thermal conductivity, Wavelength

μ — Absorption coefficient, Chemical potential, Magnetic dipole moment, Mean, SI prefix micro–, Micron, Muon, Permeability, Reduced mass

ν — Frequency, Kinematic viscosity, Neutrino

ξ — Riemann Xi function

ο -

π — Fundamental group, Conjugate momentum, Homotopy groups, Number π, Pion, Prime-counting function, Projection

ρ — Density, Electrical resistivity, Radial polar coordinate, ρ-meson

σ — Cross section, Electrical conductivity, Spin, Standard deviation, Stefan-Boltzmann constant

τ — Tau lepton, Torque, Shear stress, Time constant

υ -

φ — Angular polar coordinate, Electric potential, Euler's totient function, Golden mean, Phase, Potential energy

χ — Electric susceptibility

ψ — Quantum mechanical wavefunction, J/ψ particle

ω — Frequency (rad/s), angular velocity (rad/sec)

More

Å — angstrom

Ш — Tate-Shafarevich group (Ш(G))

ш - shuffle product

ℵ — Cardinality of infinite sets

ℶ — Cardinality of infinite sets

∂ — Partial derivative

∇ - Del operator, Gradient, Divergence, Curl

See also