The role of coupling on the statistical properties of the energy fluxes between stochastic systems at different temperatures

We experimentally study the statistical properties of the energy fluxes in two systems whose components are kept at different temperatures. The first system under consideration is an electric circuit which is composed by two resistances, kept at different temperatures and connected by a capacitance (conservative coupling) which couples the thermal noise of the two resistances. The other system is composed by two Brownian particles, trapped with optical tweezers, interacting through a dissipative hydrodynamic coupling. The particles are subjected to an effective temperature difference obtained by random forcing the position of one trap. In these two systems we measure the properties of the energy flowing between the two reservoirs. The role on these properties of the coupling and of the method used to produce the highest temperature is analyzed.