A geometric proof of the fluctuation-dissipation theorem for the $\text{KM}_{2}\text{O}$-Langevin equation
Maciej Klimek, Erlendur Karlsson, Masaya Matsuura, Yasunori Okabe · Hokkaido Mathematical Journal · 2002
We give a short proof, based on the geometry of inner product spaces, of the fluctuation-dissipation theorem that asserts applicability of the Whittle-Wiggins-Robinson algorithm in the context of the KM_{2O} -Langevin equations also in degenerate and non-stationary cases.