Related Experiment Video
Updated: Jun 2, 2026

Age-dependent Dynamics of Locomotion in Caenorhabditis elegans: A Lyapunov Exponent Analysis
Published on: September 23, 2025
Complexity and nonseparability of classical Liouvillian dynamics
1Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenia.
We introduce separability entropy, a new measure for classical Liouvillian dynamics complexity. Linear growth of this entropy indicates exponentially unstable, nonlinear, and non-Markovian dynamics, a stricter complexity criterion than Kolmogorov-Sinai entropy.
Area of Science:
- Classical dynamics
- Quantum information theory
- Statistical mechanics
Background:
- Characterizing complexity in classical Liouvillian dynamics is crucial for understanding system behavior.
- Existing entropy measures may not fully capture the intricate nature of complex dynamics.
Purpose of the Study:
- To propose a novel and simple complexity indicator for classical Liouvillian dynamics.
- To establish the relationship between this new indicator and established complexity measures.
Main Methods:
- Definition of separability entropy based on the Schmidt decomposition of phase space density.
- Analysis of the conditions under which separability entropy exhibits linear growth.
Main Results:
- Separability entropy quantifies the effective number of terms in a Schmidt decomposition.
- Linear growth of separability entropy is shown to be a stricter criterion for complexity than Kolmogorov-Sinai entropy.
Conclusions:
- Separability entropy offers a new perspective on quantifying complexity in classical dynamics.
- The linear growth of separability entropy necessitates exponentially unstable, nonlinear, and non-Markovian dynamics.
Related Concept Videos
Linear time-invariant Systems
The input-output behavior of an LTI system can be fully defined by its response to an impulsive excitation at its input. Once this impulse response is known, the system's reaction to any other input can be calculated...
Classification of Systems-I
Homogeneity dictates that if an input x(t) is multiplied by a constant c, the output y(t) is multiplied by the same constant. Mathematically, this is expressed as:
Separable Differential Equations
Classical Mechanics
BIBO stability of continuous and discrete -time systems
To determine the BIBO stability, the convolution integral is utilized when a bounded continuous-time input is applied to a Linear Time-Invariant (LTI) system.
Stability of Equilibrium Configuration
A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight...
