Feedbacks, nonlinearities and nonequilibria: A thermodynamic perspective

Area of Science:

• Thermodynamics
• Nonlinear Dynamics
• Systems Biology

Background:

• The feedback circuit approach is a key method for studying nonlinear dynamical systems.
• Understanding the role of thermodynamic constraints is crucial for analyzing system behavior.

Purpose of the Study:

• To revisit the feedback circuit approach from a thermodynamic perspective.
• To analyze the influence of nonequilibrium conditions and constraints on positive feedback circuits.

Main Methods:

• Thermodynamical analysis of feedback circuits.
• Investigation of mass action kinetics and microscopic reversibility.
• Examination of systems under nonequilibrium conditions.

Main Results:

• Non-trivial steady-state and time-dependent behaviors emerge when feedback loop strengths surpass critical values.
• Prototypical systems exhibiting multiple steady states are illustrated.
• The analysis highlights the necessity of exceeding critical feedback strengths for complex dynamics.

Conclusions:

• Thermodynamic principles are essential for understanding the behavior of nonlinear dynamical systems with feedback circuits.
• Exceeding critical feedback strengths is a fundamental requirement for observing complex behaviors in these systems.
• The study provides a framework for analyzing feedback circuits under various thermodynamic constraints.