It is defined as one over the square root of quantity one minus velocity squared over the speed of light squared.
The logarithm of the average value of this parameter for a point charge is proportional to the radiation power lost via motion through an inhomogenous medium. The parameter controlling the so-called velocity addition formula is the inverse hyperbolic cosine of this quantity. A standard derivation of this quantity considers a signal bouncing off a mirror with a stationary mirror and a mirror moving in the transverse direction, then invokes the Pythagorean theorem. This quantity it is equal to the frequency ratio in the transverse Doppler effect. The differential of the coordinate time is this quantity times the differential of the proper time. In the direction of motion, this quantity appears. It is defined as one over the square root of quantity one minus velocity squared over the speed of light squared. For 10 points, name this factor that gives the ratio of rest and observed lengths, as it appears in its namesake's special relativistic coordinate transforms.
The logarithm of the average value of this parameter for a point charge is proportional to the radiation power lost via motion through an inhomogenous medium.
Lorentz factor [or Lorentz term or Lorentz gamma; prompt on gamma]