Kinetic Theory and Mesoscopic Noise

In the theory of noise processes for mesoscopic conductors, the relationship between shot noise and hot-electron noise is absolutely fundamental to understanding the underlying microscopic fluctuations. From the vantage point of orthodox microscopics and kinetics, their relation is a long way from being settled. Its resolution calls for the tools of many-body theory. We motivate the many-body approach to noise, review the analysis of conductance and current noise within linear diffusive theories, and discuss the smooth crossover between thermal noise and shot noise. We outline a kinetic theory of nonequilibrium fluctuations, and show how this completely orthodox approach directly negates drift-diffusive explanations of the crossover.