The Greek Alphabet in Math (and Science)
The Greek alphabet appears throughout mathematics and science, not because those fields have any exclusive claim to it, but because long convention made these symbols convenient shorthand. Over time, certain letters became associated with particular ideas—\(\pi\) for the circle constant, \(\lambda\) for eigenvalues, \(\sigma\) for standard deviation—while many others remain flexible and context-dependent.
These conventions are not strict rules. They are shared habits that help readers recognize familiar patterns and reduce ambiguity. This glossary highlights common uses and also notes where an uppercase Greek letter is usually written with the same shape as an ordinary Latin capital.
Uppercase Letters
| Letter | Symbol | LaTeX | Common Uses |
|---|---|---|---|
| Alpha | \(A\) | A |
Usually not treated as a distinct Greek symbol in math fonts; often just looks like Latin capital A |
| Beta | \(B\) | B |
Usually not treated as a distinct Greek symbol in math fonts; often just looks like Latin capital B |
| Gamma | \(\Gamma\) | \\Gamma |
Gamma function, boundary curves, special functions |
| Delta | \(\Delta\) | \\Delta |
Change or difference, discriminant, symmetric difference, Laplacian in some contexts |
| Epsilon | \(E\) | E |
Usually not treated as a distinct Greek symbol in math fonts; often just looks like Latin capital E |
| Zeta | \(Z\) | Z |
Usually not treated as a distinct Greek symbol in math fonts; often just looks like Latin capital Z |
| Eta | \(H\) | H |
Usually not treated as a distinct Greek symbol in math fonts; often just looks like Latin capital H |
| Theta | \(\Theta\) | \\Theta |
Asymptotic tight bound in computer science, angles, parameter sets |
| Iota | \(I\) | I |
Usually not treated as a distinct Greek symbol in math fonts; often just looks like Latin capital I |
| Kappa | \(K\) | K |
Usually not treated as a distinct Greek symbol in math fonts; often just looks like Latin capital K |
| Lambda | \(\Lambda\) | \\Lambda |
Eigenvalue collections, cosmological constant, diagonal matrices |
| Mu | \(M\) | M |
Usually not treated as a distinct Greek symbol in math fonts; often just looks like Latin capital M |
| Nu | \(N\) | N |
Usually not treated as a distinct Greek symbol in math fonts; often just looks like Latin capital N |
| Xi | \(\Xi\) | \\Xi |
Random variables, partition functions, Riemann Xi function |
| Omicron | \(O\) | O |
Usually avoided; visually identical to Latin capital O |
| Pi | \(\Pi\) | \\Pi |
Product notation symbol by visual relation; also projection maps and other operators |
| Rho | \(P\) | P |
Usually not treated as a distinct Greek symbol in math fonts; often just looks like Latin capital P |
| Sigma | \(\Sigma\) | \\Sigma |
Summation symbol by visual relation, covariance matrices, surfaces |
| Tau | \(T\) | T |
Usually not treated as a distinct Greek symbol in math fonts; often just looks like Latin capital T |
| Upsilon | \(\Upsilon\) | \\Upsilon |
Rare; sometimes particle physics |
| Phi | \(\Phi\) | \\Phi |
Potential functions, flux, golden ratio in some contexts |
| Chi | \(X\) | X |
Usually not treated as a distinct Greek symbol in math fonts; often just looks like Latin capital X |
| Psi | \(\Psi\) | \\Psi |
Wavefunctions in quantum mechanics, special functions |
| Omega | \(\Omega\) | \\Omega |
Sample space, ohms, asymptotic lower bound |
Lowercase Letters
| Letter | Symbol | LaTeX | Common Uses |
|---|---|---|---|
| alpha | \(\alpha\) | \\alpha |
Angles, significance level in statistics, coefficients |
| beta | \(\beta\) | \\beta |
Regression coefficients, beta distribution, angles |
| gamma | \(\gamma\) | \\gamma |
Euler–Mascheroni constant, Lorentz factor, gamma distribution |
| delta | \(\delta\) | \\delta |
Small change, variation, Dirac delta or Kronecker delta depending on context |
| epsilon | \(\epsilon\) | \\epsilon |
Arbitrarily small quantity in limits; many authors prefer \\varepsilon |
| zeta | \(\zeta\) | \\zeta |
Riemann zeta function |
| eta | \(\eta\) | \\eta |
Efficiency, viscosity, Dedekind eta function |
| theta | \(\theta\) | \\theta |
Angles, parameters in statistics; many authors also use \\vartheta |
| iota | \(\iota\) | \\iota |
Inclusion map, embedding |
| kappa | \(\kappa\) | \\kappa |
Curvature, condition number |
| lambda | \(\lambda\) | \\lambda |
Eigenvalues, wavelength, decay constants |
| mu | \(\mu\) | \\mu |
Mean, coefficient of friction, measure, micro- prefix |
| nu | \(\nu\) | \\nu |
Frequency, measure, degrees of freedom in some contexts |
| xi | \(\xi\) | \\xi |
Random variables, roots, Riemann Xi-related notation in lowercase contexts |
| omicron | \(o\) | o |
Essentially unused as a distinct math symbol; no standard \\omicron command |
| pi | \(\pi\) | \\pi |
The constant \(3.14159\ldots\), circle ratio |
| rho | \(\rho\) | \\rho |
Density, radial coordinate, correlation coefficient |
| sigma | \(\sigma\) | \\sigma |
Standard deviation, stress, permutations, singular values |
| tau | \(\tau\) | \\tau |
Time constant, shear stress, torsion, sometimes \(2\pi\) |
| upsilon | \(\upsilon\) | \\upsilon |
Rare |
| phi | \(\phi\) | \\phi |
Angles, golden ratio, potentials; many authors also use \\varphi |
| chi | \(\chi\) | \\chi |
Characteristic functions, chi-square distribution, characters in number theory |
| psi | \(\psi\) | \\psi |
Wavefunctions, digamma and polygamma-related notation |
| omega | \(\omega\) | \\omega |
Angular frequency, differential forms, sample-space elements |
Notes
- The symbols
\\sumand\\prodare operators, not just the letters\\Sigmaand\\Pi, though they are visually related. - Several uppercase Greek letters are visually identical to Latin capitals in standard math fonts, which is why they are often not treated as separate symbols in practice.
- Variant forms such as
\\varepsilon,\\vartheta, and\\varphiare common and often preferred by authors for readability.