# Stochastic entropy production in the quiet Sun magnetic fields

## TL;DR

This paper demonstrates that small-scale magnetic fields in the quiet Sun follow fluctuation theorems for entropy production, revealing fundamental insights into solar magnetic energy dynamics.

## Contribution

It provides the first observational evidence that solar magnetic field fluctuations obey fluctuation theorems, linking microscopic entropy fluctuations to macroscopic solar phenomena.

## Key findings

- Entropy generated by small-scale magnetic fields obeys fluctuation theorems.
- Probability of entropy consumption is exponentially smaller than entropy generation.
- Implications for the magnetic energy budget of the Sun.

## Abstract

The second law of thermodynamics imposes an increase of macroscopic entropy with time in an isolated system. Microscopically, however, the entropy production can be negative for a single, microscopic realization of a thermodynamic process. The so-called fluctuation theorems provide exact relations between the stochastic entropy consumption and generation. Here, we analyse pixel-to-pixel fluctuations in time of small-scale magnetic fields (SSMF) in the quiet Sun observed with the SDO/HMI instrument. We demonstrate that entropy generated by SSMF obeys the fluctuation theorems. In particular, the SSMF entropy consumption probability is exactly exponentially smaller than the SSMF entropy generation probability. This may have fundamental implications for the magnetic energy budget of the Sun.