Greek alphabet

The Greek alphabet is used extensively in mathematics and the physical sciences to stand for well known constants, variables, functions, and so forth. Because many of the uppercase (or capital, or majuscule) Greek letters are indistinguishable from their counterparts in the Latin alphabet, only uses that are specifically interpreted as Greek letters should be listed below.

Name	Uppercase		Lowercase
	Symbol	Meaning	Symbol	Meaning
Alpha	$\mathrm {A}$		$\alpha$	any angle, reference angle, direction angle (x-axis), significance level (probability of a type I error); sometimes: proportional to $(\propto )$
Beta	$\mathrm {B}$	Beta function, Beta distribution	$\beta$	any angle, direction angle (y-axis), probability of a type II error, beta distribution, regression coefficient
Gamma	$\Gamma$	Gamma function, Gamma distribution	$\gamma$	any angle, direction angle (z-axis), Euler's constant, gamma distribution
Delta	$\Delta$	any change in a quantity	$\delta$	Kronecker's delta, Dirac delta function, infinitesimal change
Epsilon	$\mathrm {E}$		$\epsilon$	any positive quantity (especially a very small one)
Zeta	$\mathrm {Z}$		$\zeta$	Riemann zeta function
Eta	$\mathrm {H}$		$\eta$
Theta	$\Theta$		$\theta$	any angle
Iota	$\mathrm {I}$		$\iota$
Kappa	$\mathrm {K}$		$\kappa$	curvature of a function
Lambda	$\Lambda$		$\lambda$	(Physics) Half-life, (physics) wave-length, (differential equations) zeros of a characteristic equation, (linear algebra) eigenvalues, (probability) parameter in the Poisson distribution, Lambda Calculus
Mu	$\mathrm {M}$		$\mu$	(statistics) population mean, (mensuration) SI prefix "micro-"
Nu	$\mathrm {N}$		$\nu$
Xi	$\Xi$		$\xi$	Riemann Xi Function
Omicron	$\mathrm {O}$		$\mathrm {o}$
Pi	$\Pi$	product operator, ($\coprod$) Coproduct operator	$\pi$	Pi (constant), the ratio between a circle's diameter and circumference approximately $3.141592653\ldots$, Prime counting function
Rho	$\mathrm {P}$		$\rho$	Degree of a vertex, radius in spherical coordinates, radius of curvature of a function
Sigma	$\Sigma$	summation operator	$\sigma$	standard deviation
Tau	$\mathrm {T}$		$\tau$	Torsion of a curve, suggested as a constant representing the ratio between a circle's radius and circumference, equal to 2π
Upsilon	$\Upsilon$		$\upsilon$
Phi	$\Phi$		$\phi$	φ ($1.618033988\ldots$), angle between z-axis and radius in spherical coordinates
Chi	$\mathrm {X}$		$\chi$	(statistics) Chi-squared test
Psi	$\Psi$		$\psi$	Polygamma Function
Omega	$\Omega$		$\omega$

See also

• Mathematical symbols