Excess and loss of entropy production for different levels of coarse graining

Abstract

We investigate the effect of coarse graining on the thermodynamic properties of a system, focusing on entropy production. As a case of study, we consider a one-dimensional colloidal particle in contact with a thermal bath, moving in a sinusoidal potential and driven out of equilibrium by a small constant force. Different levels of coarse graining are evaluated: At first, we compare the results in the underdamped dynamics with those in the overdamped one (first coarse graining). For large values of the friction coefficient, the two dynamics have the same thermodynamics properties, while, for smaller friction values, the overdamped approximation produces an excess of entropy production with respect to that of the underdamped dynamics. Moreover, for further smaller values of the drag coefficient, the excess of entropy production turns into a loss. These regimes are explained by evaluating the jump statistics, observing that the inertia is able to induce multiple jumps and affect the average jump rate. The periodic shape of the potential allows us to approximate the continuous dynamics via a Markov chain after the introduction of a suitable time and space discretization (second level of coarse graining). This discretization procedure is implemented starting both from the underdamped and the overdamped evolution and is analyzed for different values of the friction coefficient.

Dynamics of inertial particles under velocity resetting

“…However, in the present model, the observable variable is not the one undergoing resets. Hence, it would be interesting to investigate bounds on the thermodynamic cost based on partial accessible information, a topic which has gained considerable attention in the past decade [74][75][76][77][78][79][80][81][82][83].…”

Variance sum rule for entropy production

“…Intuitively, the VSR (Eqs. 1 and 8) sets an energy balance between fluctuating positions and forces, both conjugated energy variables, a missing feature in the thermodynamic uncertainty relation and coarse-graining models ( 43 – 45 ). In general, the VSR captures most of σ because sampling rates, 40 kHz for OT stretching, 25 kHz for OT sensing, and 2 kHz for OM, are higher than the frequency of the active noise, ∼100 s−1 for the RBC experiments (tables S2 to S4).…”

Resolving the dynamic properties of entangled linear polymers in non-equilibrium coarse grain simulation with a priori scaling factors

“…27,28 However, the influence of such entropy loss on other physical properties is still under investigation, 29 especially for the nonequilibrium state. 30 Some recent studies used excessive entropy scaling to predict the acceleration in the CG dynamics, 31,32 but the conclusions are not transferred to physical properties like heat capacity, modulus, and viscosity.…”