scholarly journals Mean-field and graph limits for collective dynamics models with time-varying weights

2021 ◽  
Vol 299 ◽  
pp. 65-110
Author(s):  
Nathalie Ayi ◽  
Nastassia Pouradier Duteil
2018 ◽  
Vol 29 (4) ◽  
pp. e2504 ◽  
Author(s):  
Shelley H. Liu ◽  
Jennifer F. Bobb ◽  
Birgit Claus Henn ◽  
Lourdes Schnaas ◽  
Martha M. Tellez-Rojo ◽  
...  

2021 ◽  
Vol 44 (2) ◽  
Author(s):  
Martin Wittmann ◽  
Mihail N. Popescu ◽  
Alvaro Domínguez ◽  
Juliane Simmchen

Abstract For monolayers of chemically active particles at a fluid interface, collective dynamics is predicted to arise owing to activity-induced Marangoni flow even if the particles are not self-propelled. Here, we test this prediction by employing a monolayer of spherically symmetric active $$\hbox {TiO}_2$$ TiO 2 particles located at an oil–water interface with or without addition of a nonionic surfactant. Due to the spherical symmetry, an individual particle does not self-propel. However, the gradients produced by the photochemical fuel degradation give rise to long-ranged Marangoni flows. For the case in which surfactant is added to the system, we indeed observe the emergence of collective motion, with dynamics dependent on the particle coverage of the monolayer. The experimental observations are discussed within the framework of a simple theoretical mean-field model. Graphic abstract


2017 ◽  
Vol 43 (3) ◽  
pp. 309-312 ◽  
Author(s):  
V. I. Ponomarenko ◽  
D. D. Kul’minskii ◽  
A. S. Karavaev ◽  
M. D. Prokhorov

2006 ◽  
Vol 115 (3) ◽  
pp. 567-599 ◽  
Author(s):  
N. Hinohara ◽  
T. Nakatsukasa ◽  
M. Matsuo ◽  
K. Matsuyanagi

2019 ◽  
Vol 29 (04) ◽  
pp. 681-716 ◽  
Author(s):  
Sean McQuade ◽  
Benedetto Piccoli ◽  
Nastassia Pouradier Duteil

This paper introduces an augmented model for first-order opinion dynamics, in which a weight of influence is attributed to each agent. Each agent’s influence on another agent’s opinion is then proportional not only to the classical interaction function, but also to its weight. The weights evolve in time and their equations are coupled with the opinions’ evolution. We show that the well-known conditions for convergence to consensus can be generalized to this framework. In the case of interaction functions with bounded support, we show that constant weights lead to clustering with conditions similar to those of the classical model. Four specific models are designed by prescribing a specific weight dynamics, then the convergence of the opinions and the evolution of the weights for each of them are studied. We prove the existence of different long-term behaviors, such as emergence of a single leader and emergence of two co-leaders. Then we illustrate them via numerical simulations. Last, a statistical analysis is provided for the speed of convergence to consensus and for the clustering behavior of each model, together with a comparison to the classical opinion dynamics with constant equal weights.


2005 ◽  
Vol 16 (10) ◽  
pp. 1507-1517 ◽  
Author(s):  
A. O. SOUSA ◽  
K. MALARZ ◽  
S. GALAM

Galam reshuffling introduced in opinion dynamics models, is investigated under the nearest neighbor Ising model on a square lattice using Monte Carlo simulations. While the corresponding Galam analytical critical temperature TC≈3.09 [J/kB] is recovered almost exactly, it is proved to be different from both values, not reshuffled (TC =2/ arcsinh (1)≈2.27 [J/kB]) and mean-field (TC =4 [J/kB]). On this basis, gradual reshuffling is studied as function of 0≤p≤1 where p measures the probability of spin reshuffling after each Monte Carlo step. The variation of TC as function of p is obtained and exhibits a nonlinear behavior. The simplest Solomon network realization is noted to reproduce Galam p =1 result. Similarly to the critical temperature, critical exponents are found to differ from both, the classical Ising case and the mean field values.


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