**Commonly Used Greek Letters in Subjects**

Lower case | Capital | Name | |
---|---|---|---|

alpha | Angular acceleration Linear expansion Coefficient Alpha particle (helium nucleus) Fine Structure Constant | ||

beta | Beta particle — high energy electron Sound intensity | ||

gamma | Gamma ray (high energy EM wave) Ratio of heat capacities (in an ideal gas) Relativistic correction factor | ||

delta | Δ="Change in" δ="Infinitessimal change in" | ||

epsilon | Emissivity Strain Permittivity EMF | ||

zeta | (no common use) | ||

eta | Viscosity Energy efficiency | ||

theta | Angle (°, rad) Temperature | ||

iota | The lower case is rarely used, while is sometimes used for the identity matrix or the moment of inertia. Note that is not to be confused with the Roman character i; (which has a dot and is much more widely used in mathematics and physics). | ||

kappa | Spring constant Dielectric constant | ||

lambda | Wavelength Thermal conductivity Constant Eigenvalue of a matrix Linear density | ||

mu | Coefficient of friction Electrical mobility Reduced mass Permeability | ||

nu | Frequency | ||

xi | Damping cofficient | ||

omicron | (no common use) | ||

pi | Product symbol Π Circle number π: = 3.14159... | ||

rho | Volume density Resistivity | ||

sigma | Sum symbol Boltzmann constant Electrical conductivity Uncertainty Stress Surface density | ||

tau | Torque Tau particle (a lepton) Time constant | ||

upsilon | (pending) | ||

phi | Magnetic/electric flux Angle (°, rad) | ||

chi | Rabi frequency (lasers) Susceptibility | ||

psi | Wave function | ||

omega | Ohms (unit of electrical resistance) ω Angular velocity |