Energy spectrum of a Langevin oscillator
  We derive analytical solutions for the autocorrelation and cross-correlation functions of the kinetic, potential and total energy of a Langevin oscillator. These functions are presented in both the time and frequency domains and validated by independent numerical simulations. The results are applied to address the long-standing issue of temperature fluctuations in canonical systems. 
Y. Mishin and J. Hickman
cond-mat.other cond-mat.stat-mech