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The area of population dynamics has a rich history of the development and analysis of models of biological and social phenomena using ordinary differential equations. This paper describes a method for understanding the influence one…

Populations and Evolution · Quantitative Biology 2022-03-09 John Hayward , Paul A. Roach

We analyze the nonlinear relaxation of a complex ecosystem composed of many interacting species. The ecological system is described by generalized Lotka-Volterra equations with a multiplicative noise. The transient dynamics is studied in…

Statistical Mechanics · Physics 2016-11-23 M. A. Cirone , F. de Pasquale , B. Spagnolo

Many growing phenomena in both nature and society can be predicted with sigmoid function. The growth curve of the level of urbanization is a typical S-shaped one, and can be described by using logistic function. The logistic model implies a…

Physics and Society · Physics 2018-12-19 Yanguang Chen

Ecological resilience refers to the ability of a system to retain its state when subject to state variables perturbations or parameter changes. While understanding and quantifying resilience is crucial to anticipate the possible regime…

Dynamical Systems · Mathematics 2019-05-10 Artur César Fassoni , Denis de Carvalho Braga

Mathematical models of spatial population dynamics typically focus on the interplay between dispersal events and birth/death processes. However, for many animal communities, significant arrangement in space can occur on shorter timescales,…

Populations and Evolution · Quantitative Biology 2019-06-06 Jonathan R. Potts , Mark A. Lewis

The dynamics of dislocations can be formulated in terms of the evolution of continuous variables representing dislocation densities ('continuum dislocation dynamics'). We show for various variants of this approach that the resulting models…

Materials Science · Physics 2024-10-23 Yufan Zhang , Ronghai Wu , Michael Zaiser

We study closed systems of particles that are subject to stochastic forces in addition to the conservative forces. The stochastic equations of motion are set up in such a way that the energy is strictly conserved at all times. To ensure…

Statistical Mechanics · Physics 2022-10-05 Tânia Tomé , Mário J. de Oliveira

An operator-valued quantum phase space formula is constructed. The phase space formula of Quantum Mechanics provides a natural link between first and second quantization, thus contributing to the understanding of quantization problem. By…

Mathematical Physics · Physics 2017-03-16 Dong-Sheng Wang

A formalism for quantum many-body systems is proposed through a semiclassical treatment in phase space, allowing us to establish a stochastic thermodynamics incorporating quantum statistics. Specifically, we utilize a stochastic…

Statistical Mechanics · Physics 2024-12-23 Zhaoyu Fei

The relative importance of Lagrangian and population dynamics on spatial pattern formation in the distribution of plankton near the ocean's surface is investigated. Phytoplankton and zooplankton are treated as biologically interacting…

Chaotic Dynamics · Physics 2007-05-23 M. J. Olascoaga , F. J. Beron-Vera , M. G. Brown , H. Koçak

In classical statistical mechanics, the partition function is defined in phase space. We extend this concept to quantum statistical mechanics using Bohmian trajectories. The quantum partition function in phase space captures the ensemble of…

Quantum Physics · Physics 2025-11-20 Bingyu Cui

Recently the phase space structures governing reaction dynamics in Hamiltonian systems have been identified and algorithms for their explicit construction have been developed. These phase space structures are induced by saddle type…

Chaotic Dynamics · Physics 2015-05-28 Unver Ciftci , Holger Waalkens

We present the basic formulation of Hamilton dynamics in complex phase space. We extend the Hamilton's function by including the imaginary part and find out the corresponding Hamilton's canonical equation of motion. Example of simple…

Classical Physics · Physics 2019-06-18 Muhammad Adnan Shahzad

Transport in Hamiltonian systems with weak chaotic perturbations has been much studied in the past. In this paper, we introduce a new class of problems: transport in Hamiltonian systems with slowly changing phase space structure that are…

Chaotic Dynamics · Physics 2019-10-02 Freddy Bouchet , Eric Woillez

Neural mass models describe the mean-field dynamics of populations of neurons. In this work we illustrate how fundamental ideas of physics, such as energy and conserved quantities, can be explored for such models. We show that…

Neurons and Cognition · Quantitative Biology 2025-09-15 Daniele Andrean , Morten Gram Pedersen

Bayesian mechanics provides a framework that addresses dynamical systems that can be conceptualised as Bayesian inference. However, elucidating the requisite generative models is essential for empirical applications to realistic…

Neurons and Cognition · Quantitative Biology 2024-12-02 Takuya Isomura

Collective motion in biology is often modelled as a dynamical system, in which individuals are represented as particles whose interactions are determined by the current state of the system. Many animals, however, including humans, have…

Biological Physics · Physics 2018-01-03 P. Gerlee , K. Tunstrøm , T. Lundh , B. Wennberg

This work reflects on mechanics as an epistemological framework on the state of a physical system to regard dynamics as the distribution of mechanical properties over spacetime coordinates. The resulting distribution is taken to be the…

General Physics · Physics 2026-04-29 VS Morales-Salgado

The paper considers some class of dynamical systems that called density systems. For such systems the derivative of quadratic function depends on so-called density function. The density function is used to set the properties of phase space,…

Systems and Control · Electrical Eng. & Systems 2023-04-12 Igor Furtat

Evolutionary game theory has been successfully used to investigate the dynamics of systems, in which many entities have competitive interactions. From a physics point of view, it is interesting to study conditions under which a coordination…

Physics and Society · Physics 2015-05-14 Dirk Helbing , Anders Johansson