Gamma (Γ γ) is the 3rd letter of the Greek alphabet and has a numeric value of 3.
It gives its name to several things:
- Gamma rays, and Gamma-ray astronomy
- in mathematics, Gamma function used to extend the concept of factorial to complex numbers
- Gamma characteristic power law, and gamma correction in television and computer display systems. gamma refers to the exponent in a power-law relationship between video or pixel values and the displayed brightness.
- In the game of Tetris, gamma is another name for the J tetromino.
- Gamma can refer to the adiabatic index of a gas.