  The quantum Langevin equation as obtained from the independent-oscillator
model describes a strong-coupling situation, devoid of the Born-Markov
approximation that is employed in the context of the
Gorini-Kossakowski-Sudarshan-Lindblad equation. The question we address is what
happens when we implement such 'Born-Markov'-like approximations at the level
of the quantum Langevin equation for a harmonic oscillator which carries a
noise term satisfying a fluctuation-dissipation theorem. In this backdrop, we
also comment on the rotating-wave approximation.
