Fluctuations of absorption of interacting diffusing particles by multiple absorbers.

Area of Science:

• Statistical Physics
• Non-equilibrium Systems
• Complex Systems Modeling

Background:

• Living cells sense their environment using multiple receptors distributed across their surface.
• Understanding particle absorption fluctuations is crucial for modeling biological sensing and transport phenomena.
• Previous research focused on fluctuations of single particle currents, limiting scope for multi-receptor systems.

Purpose of the Study:

• To analyze particle absorption fluctuations in a 3D domain with multiple absorbing patches.
• To extend macroscopic fluctuation theory to calculate the covariance matrix for particle absorption by different patches.
• To explore the relationship between absorption statistics, transport coefficients, geometry, and related physical systems.

Main Methods:

• Application of macroscopic fluctuation theory (MFT) to a system of interacting diffusing particles.
• Calculation of the covariance matrix for particle absorption across multiple distinct patches.
• Analysis of the particle flux field and its statistical properties.

Main Results:

• Identified a condition where absorption correlations are determined solely by transport coefficients, independent of geometry.
• Demonstrated that fluctuating particle flux fields typically exhibit vorticity.
• Established a link between multi-patch absorption statistics and 1D non-equilibrium steady-state current statistics.

Conclusions:

• The study provides a theoretical framework for understanding multi-receptor sensing and particle absorption.
• Findings offer insights into the role of transport coefficients and vorticity in complex particle dynamics.
• Connections are drawn to electric current statistics in conductors and wave transmission in disordered media.