X1-194 (2026/02/03)
The harmonic oscillator, with friction and noise IV
A harmonic oscillator with linear friction is studied, to which a white noise also applies a force. The mobility and the diffusion coefficient are defined and, using the time-dependences of the two-point function for this oscillator, when there is no restoring force which is linear with the position, a relation between the mobility and the diffusion coefficient is obtained.