Energy dissipation and violation of the fluctuation-response relation for harmonic oscillators described by the generalized Langevin equation

The generalized Langevin equation (GLE) satisfied by harmonic oscillators coupled to a heat bath is transformed into an equality between the rate of energy dissipation and an extent of violation of the fluctuation-response relation. Its significance is discussed. When the system reaches a stationary state and a single harmonic oscillator's frequency is set to zero, the equality reduces to a fluctuation-dissipation relation, which is slightly different from the usual Kubo's formalism.