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While compactness is an essential assumption for many results in dynamical systems theory, for many applications the state space is only locally compact. Here we provide a general theory for compactifying such systems, i.e. embedding them…

Dynamical Systems · Mathematics 2010-04-05 Ethan Akin , Joseph Auslander

Superstatistics is a widely employed tool of non-equilibrium statistical physics which plays an important role in analysis of hierarchical complex dynamical systems. Yet, its "canonical" formulation in terms of a single nuisance parameter…

Statistical Finance · Quantitative Finance 2017-11-10 Petr Jizba , Jan Korbel , Hynek Lavička , Martin Prokš , Václav Svoboda , Christian Beck

The hierarchical structure inherent in many real-world datasets makes the modeling of such hierarchies a crucial objective in both unsupervised and supervised machine learning. While recent advancements have introduced deep architectures…

Machine Learning · Computer Science 2025-12-19 Emanuele Palumbo , Moritz Vandenhirtz , Alain Ryser , Imant Daunhawer , Julia E. Vogt

Many social and biological systems are characterized by enduring hierarchies, including those organized around prestige in academia, dominance in animal groups, and desirability in online dating. Despite their ubiquity, the general…

Social and Information Networks · Computer Science 2022-04-27 Mari Kawakatsu , Philip S. Chodrow , Nicole Eikmeier , Daniel B. Larremore

Group-based reinforcement can induce discontinuous transitions from inactive to active phases in higher-order contagion models. However, these results are typically obtained on static interaction structures or within mean-field…

We study the relaxation dynamics of systems of straight, parallel crystal dislocations, starting from initially random and uncorrelated positions of the individual dislocations. A scaling model of the relaxation process is constructed by…

Materials Science · Physics 2009-03-28 Ferenc F. Csikor , Michael Zaiser , Péter Dusán Ispánovity , István Groma

The presence and evolution of defects that appear in the manufacturing process play a vital role in the failure mechanisms of engineering materials. In particular, the collective behavior of dislocation dynamics at the mesoscale leads to…

Materials Science · Physics 2022-05-13 Eduardo Augusto Barros de Moraes , Marta D'Elia , Mohsen Zayernouri

Plastic deformation In crystalline materials is controlled by the motion and interactions of dislocations [AND 17]. Discrete Dislocation Dynamics (DDD) simulations have now existed for about 25 years to investigate plastic flow at the…

Materials Science · Physics 2020-01-07 Sylvain Queyreau

We wish to understand the macroscopic plastic behaviour of metals by upscaling the micro-mechanics of dislocations. We consider a highly simplified dislocation network, which allows our microscopic model to be a one dimensional particle…

Mathematical Physics · Physics 2019-02-20 P. van Meurs , A. Muntean , M. A. Peletier

Concepts of everyday use like energy, heat, and temperature have acquired a precise meaning after the development of thermodynamics. Thermodynamics provides the basis for understanding how heat and work are related and with the general…

Statistical Mechanics · Physics 2007-05-23 D. Reguera , J. M. Rubi , J. M. G. Vilar

Social hierarchy is central to decision-making in the coordinated movement of many swarming species. Here we propose a hierarchical swarm model in the spirit of the Vicsek model of self-propelled particles. We show that, as the hierarchy…

Biological Physics · Physics 2020-10-28 Tingting Xue , Xu Li , Peter Grassberger , Li Chen

Homogenisation empowers the efficient macroscale system level prediction of physical scenarios with intricate microscale structures. Here we develop an innovative powerful, rigorous and flexible framework for asymptotic homogenisation of…

Dynamical Systems · Mathematics 2025-04-08 A. J. Roberts

While generic competitive systems exhibit mixtures of hierarchy and cycles, real-world systems are predominantly hierarchical. We demonstrate and extend a mechanism for hierarchy; systems with similar agents approach perfect hierarchy in…

Populations and Evolution · Quantitative Biology 2024-02-12 Christopher Cebra , Alexander Strang

The emergence and decline of democratic systems worldwide raises fundamental questions about the dynamics of political change. Contrary to the idea of a stable endpoint of liberal democracy, recent backsliding towards less democratic…

Statistical Mechanics · Physics 2026-03-09 Joshua Uhlig , Paula Pirker-Díaz , Matthew Wilson , Ralf Metzler , Karoline Wiesner

In continuum models of dislocations, proper formulations of short-range elastic interactions of dislocations are crucial for capturing various types of dislocation patterns formed in crystalline materials. In this article, the continuum…

Materials Science · Physics 2016-08-12 Yichao Zhu , Xiaohua Niu , Yang Xiang

We develop a master equation formalism to describe the evolution of the average density matrix of a closed quantum system driven by a stochastic Hamiltonian. The average over random processes generally results in decoherence effects in…

Quantum Physics · Physics 2011-11-30 Li Yu , Daniel F. V. James

Percolation is the simplest fundamental model in statistical mechanics that exhibits phase transitions signaled by the emergence of a giant connected component. Despite its very simple rules, percolation theory has successfully been applied…

Statistical Mechanics · Physics 2015-06-09 Abbas Ali Saberi

Ecosystems display a complex spatial organization. Ecologists have long tried to characterize them by looking at how different measures of biodiversity change across spatial scales. Ecological neutral theory has provided simple predictions…

Populations and Evolution · Quantitative Biology 2017-12-13 Simone Pigolotti , Massimo Cencini , Daniel Molina , Miguel A. Muñoz

We consider the time evolution of a one dimensional $n$-gradient continuum. Our aim is to construct and analyze discrete approximations in terms of physically realizable mechanical systems, called microscopic because they are living on a…

Mathematical Physics · Physics 2015-05-06 Antonio Carcaterra , Francesco dell'Isola , Raffaele Esposito , Mario Pulvirenti

A long-standing goal of materials science is to understand, predict and control the evolution of microstructures in crystalline materials. Most microstructure evolution is controlled by interface motion; hence, the establishment of rigorous…

Materials Science · Physics 2022-02-14 Jian Han , David J. Srolovitz , Marco Salvalaglio