Efficiency fluctuations of small machines with unknown losses

TL;DR

This paper investigates efficiency fluctuations in small thermodynamic machines with unknown losses, extending previous models by considering three processes and analyzing the impact of unmeasurable or efficiency-reducing losses.

Contribution

It generalizes the analysis of efficiency fluctuations to include three processes and accounts for unmeasurable or loss-inducing third processes.

Findings

Analyzes the effect of unknown losses on efficiency fluctuations.

Provides general framework for machines with three processes.

Includes specific examples illustrating the impact of unmeasurable losses.

Abstract

The efficiency statistics of a small thermodynamic machine has been recently investigated assuming that the total dissipation was a linear combination of two currents: the input and output currents. Here, we relax this standard assumption and reconsider the question of the efficiency fluctuations for a machine involving three different processes, first in full generality and second for two different examples. Since the third process may not be measurable and/or may decrease the machine efficiency, our motivation is to study the effect of unknown losses in small machines.