Limitations on the Utility of Exact Master Equations
arXiv:quant-ph/0504132 · doi:10.1016/j.aop.2005.04.008
Abstract
The low temperature solution of the exact master equation for an oscillator coupled to a linear passive heat bath is known to give rise to serious divergences. We now show that, even in the high temperature regime, problems also exist, notably the fact that the density matrix is not necessarily positive.