There exists a most challenging and interesting family of collective responses of a complex system - in particular resonant behaviors - that can be induced by noise, heterogeneity of the units, or their interplay; stochastic resonance, diversity induced resonance, and coherence resonance represent some popular examples.
Effect of diversity distribution symmetry on global oscillations of networks of excitable units,
Stefano Scialla, Marco Patriarca, Els Heinsalu, Marius E. Yamakou, Julyan H. E. Cartwright,
Phys. Rev. E 112, 054201 (2025)
https://doi.org/10.1103/lvb3-dc11 arXiv:2507.09804
Dynamical equivalence between resonant translocation of a polymer chain and diversity-induced resonance,
Marco Patriarca, Stefano Scialla, Els Heinsalu, Marius E. Yamakou, Julyan H. E. Cartwright,
Chaos 35, 073115 (2025)
https://doi.org/10.1063/5.0262633 https://arxiv.org/abs/2502.00900
Are “hubs” in beta-cell clusters an emergent network property or do they exist independently?
Patriarca, Marco; Scialla, Stefano; Yamakou, Marius; Heinsalu, Els; Cartwright, Julyan H.E.
Acta Physiol, 239: e14044
doi: 10.1111/apha.14044
Diversity-induced decoherence
Marius E. Yamakou, Els Heinsalu, Marco Patriarca, and Stefano Scialla,
Phys. Rev. E 106, L032401 (2022)
doi: 10.1103/PhysRevE.106.L032401 https://arxiv.org/abs/2206.08064
The interplay between diversity and noise in an excitable cell network model,
Stefano Scialla, Marco Patriarca, Els Heinsalu.
Europhysics Letters 137, 51001 (2022) doi: 10.1209/0295-5075/ac5cdb arXiv:2203.12506
Hubs, diversity, and synchronization in FitzHugh-Nagumo oscillator networks: Resonance effects and biophysical implications,
Stefano Scialla, Alessandro Loppini, Marco Patriarca, and Els Heinsalu.
Phys. Rev. E 103, 052211 (2021) doi:10.1103/PhysRevE.103.052211 arXiv:2105.05652
Constructive effects of diversity in a multi-neuron model of the homeostatic regulation of the sleep–wake cycle
M. Patriarca, E. Hernández-García, and R. Toral
Chaos, Solitons & Fractals 81, 567-574 (2015)
doi:10.1016/j.chaos.2015.09.010
M. Patriarca, S. Postnova, H.A. Braun, E. Hernandez-Garcia, and R. Toral
Diversity and Noise Effects in a Model of Homeostatic Regulation of the Sleep-Wake Cycle
PLoS Comput. Biol. 8(8) (2012) e1002650
doi:10.1371/journal.pcbi.1002650
arXiv:1209.5046
Modelling the homeostatic regulation of the sleep-wake cycle: role of diversity
M. Patriarca, S. Postnova, H.A. Braun, E. Hernández-García, R. Toral
NOLTA2012, International Symposium on Nonlinear Theory and its Applications, Majorca, Spain, October 22-26, 2012
IEICE Proceeding Series, Vol. 1 (2014), p. 365-368 🔓
E. Heinsalu, M. Patriarca, and F. Marchesoni
Stochastic resonance in bistable confining potentials. On the role of confinement
Eur. J. Phys. B 69 1 (2009) 19
doi:10.1140/epjb/e2009-00050-6
arXiv:0901.2523
E. Heinsalu, M. Patriarca, and F. Marchesoni
Dimer diffusion in a washboard potential
Phys. Rev. E 77, 021129 (2008)
doi:10.1103/PhysRevE.77.021129
arXiv:0708.2858
Classical and quantum Brownian motion in an electromagnetic field
M. Patriarca and P. Sodano
Fortschritte der Physik 65 (6-8), 1600058 (2017)
doi:10.1002/prop.201600058
arxiv:1605.04698
M. Patriarca
Feynman-Vernon model for a moving thermal environment
Physica E 29 (2005) 243
doi:10.1016/j.physe.2005.05.021
https://arxiv.org/abs/1803.10300
B.L. Altschuler, C. Biagini, and M. Patriarca
Quantum chaos and transport in mesoscopic systems
in: Field Theories for low dimensional systems, G. Morandi et al. editors,
Springer Series in Solid-State Sciences, vol 131, Springer, Berlin (2000), p. 235-269
doi:10.1007/978-3-662-04273-1_7
M. Patriarca
Quantum mechanical versus stochastic processes in path integration
in: Path Integrals from peV to TeV: 50 years after Feynman’s Paper
R. Casalbuoni et al. editors, World Scientific, Singapore, 1999, p.589
arxiv:1801.00510
C. Presilla, R. Onofrio, and M. Patriarca
Classical and quantum measurements of position
J. Phys. A 30(21) (1997) 7385
doi:10.1088/0305-4470/30/21/014 arXiv:hep-th/9406024
M. Patriarca
Statistical correlations in the oscillator model of quantum dissipative systems
Il Nuovo Cimento B 111 (1996) 61
doi:10.1007/BF02726201 arxiv:1801.02429
F. Illuminati, M. Patriarca, and P. Sodano
Quantum dissipation in non-homogeneous environments
in: Fluctuation Phenomena: Disorder and Nonlinearity
A.R. Bishop, S. Jimenez and L. Vazquez editors, World Scientific, Singapore (1995), p.53.
doi:10.1142/9789814503877_0012
F. Illuminati, M. Patriarca, and P. Sodano
Classical and quantum dissipation in nonhomogeneous environments
Physica A 211 (1994) 449
doi:10.1016/0378-4371(94)00171-5 arXiv:hep-th/9406024
M. Patriarca
Boundary conditions for the Schrödinger equation in the simulation of quantum systems
Phys. Rev. E 50 (1994) 1616
doi:10.1103/PhysRevE.50.1616 & Erratum doi:10.1103/b6qb-59f6
M. Patriarca
Sistemi Quantistici in Ambienti Dissipativi, Tesi di Dottorato
[English translation: Quantum Systems in Dissipative Environments, Phd Thesis]
University of Perugia (1993)
F. A. Gianturco, M. Patriarca, and O. Roncero
Resonant states and photodissociation cross sections in protonated rare gases
Molecular Physics 67 (1989) 281
doi:10.1080/00268978900101081
F. A. Gianturco and M. Patriarca
Accurate Ne-H+ and Ar-H+ interactions from spectroscopic and scattering states
Il Nuovo Cimento 11 D (1989) 1287
doi:10.1007/BF02450546
M. Patriarca
Ioni Molecolari semplici, Tesi di Laurea
[English translation: Simple Molecular Ions, Master Thesis]
La Sapienza University, Rome (1986)
The ubiquitous presence of power laws in natural phenomena reveals general features of a complex system such as the presence of noise and fluctuations, on one hand, and heterogeneity of the constituent units and their interactions, on the other hand.
The microscopic origin of the Pareto law and other power-law distributions
M. Patriarca, E. Heinsalu, A. Chakraborti, and K. Kaski
in: Econophysics and Sociophysics: Recent Progress and Future Directions
F. Abergel et al. editors, Springer (2017), p. 159-176.
doi:10.1007/978-3-319-47705-3_12
Kinetic Exchange Models as D Dimensional Systems: A Comparison of Different Approaches
M. Patriarca, E Heinsalu, A Singh, A Chakraborti
in: Econophysics and Sociophysics: Recent Progress and Future Directions
F. Abergel et al. editors, Springer (2017), p 147-158.
doi:10.1007/978-3-319-47705-3_11
Previous version Thermal Equilibrium in D-dimensions: From Fluids and Polymers to Kinetic Wealth Exchange Models arxiv.org:1610.03367
Power-laws as statistical mixtures
M. Patriarca, E. Heinsalu, L. Marzola, A. Chakraborti, and K. Kaski
In: Proceedings of ECCS 2014: European Conference on Complex Systems, 271-282 (2016)
doi:10.1007/978-3-319-29228-1_23
A. Chakraborti and M. Patriarca
A variational principle for the Pareto power law
Phys. Rev. Lett. 103 (2009) 228701
doi:10.1103/PhysRevLett.103.228701
arXiv:cond-mat/0605325
Here are some examples of diversity-induced power laws taken from kinetic wealth exchange models, a family of models of wealth and income dynamics.
Kinetic models of immediate exchange
E. Heinsalu and M. Patriarca
The European Physical Journal B 87, 170 (2014)
doi:10.1140/epjb/e2014-50270-6
arxiv:1505.01274
M. Patriarca, A. Chakraborti, E. Heinsalu, and G. Germano
Relaxation in Statistical Many-agent Economy Models
Eur. Phys. J. B 57 (2007) 219
doi:10.1140/epjb/e2007-00122-7
arXiv:physics/0608174
M. Patriarca, A. Chakraborti, and G. Germano
Influence of saving propensity on the power-law tail of wealth distribution
Physica A 369 (2006) 723
doi:10.1016/j.physa.2006.01.091
arXiv:physics/0506028
M. Patriarca, A. Chakraborti, K. Kaski, and G. Germano
Kinetic theory models for the distribution of wealth: power law from overlap of exponentials
in: Econophysics of Wealth Distributions, Econophys-Kolkata 1, A. Chatterjee, S.Yarlagadda, B.K. Chakrabarti, Eds., Springer, 2005
doi:10.1007/88-470-0389-X_10
arXiv:physics/0504153
In many ways, linguistics has been an interdisciplinary discipline (with a large overlap with the current complexity science) since its beginning.
The reason is that its subject of study, that is language, has many peculiar features that make it an evolving and adapting systems with different levels of complexity. That is aso the reason why complex systems theory and its tools can be applied effectively to linguistics, both in terms of general concepts and practical applications.
Language competition, evolution, and spreading processes can be described by different types models that describe the dynamics at different coarse grained levels, from microscopic heterogeneous many-agent models to mesoscopic reaction-diffusion models, from statistical models of word sequence to generative grammars.
Learning thresholds lead to stable language coexistence,
Mikhail V. Tamm, Els Heinsalu, Stefano Scialla, Marco Patriarca,
https://doi.org/10.1103/PhysRevE.111.024304 arXiv:2406.14522
Language Dynamics: Complex Systems Approaches,
Els Heinsalu, Marco Patriarca, David Sanchez,
in: Reference Collection in Social Sciences,
International Encyclopedia of Language and Linguistics, 3rd edition, Elsevier 2025
https://doi.org/10.1016/B978-0-323-95504-1.00991-1
Role of zealots in the spread of linguistic traits,
V. Dornelas, C. Anteneodo, R. Nunes, E. Heinsalu, M. Patriarca,
Phys. Rev. E 112, 044303
https://link.aps.org/doi/10.1103/t4pt-zdc3 https://arxiv.org/abs/2508.01500
Complexity in Language Variation and Change (Research Topic Editorial)
Els Heinsalu, Marco Patriarca, and David Sanchez,
Frontiers in Complex Systems, Vol. 2 (2024)
doi: 10.3389/fcpxs.2024.1497038 🔓
The article collection Complexity in Language Variation and Change can be found at:
https://www.frontiersin.org/research-topics/52099/complexity-in-language-variation-and-change/articles
Language dynamics model with finite-range interactions influencing the diffusion of linguistic traits and human dispersal,
Clément Zankoc, Els Heinsalu, Marco Patriarca,
European Physical Journal B 97, 66 (2024)
https://doi.org/10.1140/epjb/s10051-024-00706-3
A three-state language competition model including language learning and attrition,
Stefano Scialla, Jens-Kristjan Liivand, Marco Patriarca, Els Heinsalu,
Front. Complex Syst. 1-1266733 (2023),
https://doi.org/10.3389/fcpxs.2023.1266733 🔓
The Physics of Languages
Marco Patriarca, Els Heinsalu, and David Sánchez
Physics World, 13 June 2023
https://physicsworld.com/a/the-physics-of-languages/
The role of bilinguals in the Bayesian naming game,
Gionni Marchetti, Marco Patriarca, Els Heinsalu.
Physica D 428, 133062 (2021)
doi:10.1016/j.physd.2021.133062 arXiv:2106.00069
"Languages in Space and Time: Models and Methods from Complex Systems Theory"
M. Patriarca, E. Heinsalu, and J.L. Leonard,
Series Physics of Society: Econophysics and Sociophysics
Cambridge University Press (2020) ISBN 978-1-108-48065-9
A Bird’s-Eye View of Naming Game Dynamics: From Trait Competition to Bayesian Inference,
G. Marchetti, M. Patriarca, and E. Heinsalu,
Chaos 30, 063119 (2020)
doi:10.1063/5.0009569
arXiv:2004.01994
A Bayesian Approach to the Naming Game Model,
G. Marchetti, M. Patriarca, and E. Heinsalu,
Frontiers in Physics 8, 10 (2020)
doi:10.3389/fphy.2020.00010 🔓
arXiv:1911.13012
Applicazioni alla linguistica dei metodi e modelli della teoria dei sistemi complessi
M. Patriarca, E. Heinsalu, and J.L. Léonard
In: "Mutamento Linguistico e Biodiversità", Il Calamo, Roma, 2018, p. 103–143
Atti del XLI Convegno Società Italiana di Glottologia, Perugia, 1-3 dicembre 2016;
L. Costamagna et al. editors, ISBN: 9788898640317,
Biblioteca della Società Italiana di Glottologia 41 p. 103–143 🔓
The role of dispersal in competition success and in the emerging diversity
E. Heinsalu, D. Navidad Maeso, and M. Patriarca
The European Physical Journal B 91, 255 (2017)
https://doi.org/10.1140/epjb/e2018-90372-5
arxiv:2004.06088
Patterns of Linguistic Diffusion in Space&Time: The Case of Mazatec
J.-L. Léonard, E. Heinsalu, and M. Patriarca,
in: Econophysics and Sociophysics: Recent Progress and Future Directions
F. Abergel et al. editors, Spriger (2017), p.227-251.
doi:10.1007/978-3-319-47705-3_17
arXiv:1612.02994
Modeling Regional Variation from EAS: Complexity and Communal Aggregates
J.L. Léonard, E. Heinsalu, M. Patriarca, and P. Darlu
Linguistic variation in the basque and education-1 (2015), Servicio Editorial de la Universidad del País Vasco, ISBN: 978-84-9082-278-4, p. 145-172 🔓
Variation dialectal del Tseltal Maya (Maya occidental) en los ámbitos morfológico, fonológico y léxico: un enfoque holístico del diasistema
G. Polian, J.L. Léonard, E. Heinsalu, M. Patriarca
in: Patterns in Mesoamerican Morphology, J.L. Léonard and A. Kihm editors
Michel Houdiard Éditeur (2014), p. 280
The role of bilinguals in language competition
E. Heinsalu, M. Patriarca, and J.L. Léonard
Advances in Complex Systems 17 (01), 1450003 (2014)
doi:10.1142/S0219525914500039
M. Patriarca, X. Castelló, J.R. Uriarte, V.M. Eguı́luz, and M. San Miguel
Modeling two-language competition dynamics
Advances in Complex Systems 15 (2012) 1250048
doi:10.1142/S0219525912500488
arXiv:1206.2960
M. Patriarca and E. Heinsalu
Influence of geography on language competition
Physica A 388 (2009) 174
doi:10.1016/j.physa.2008.09.034
arxiv.org:0807.3100
M. Patriarca and T. Leppänen
Modelling language competition
Physica A 338 (2004) 296
doi:10.1016/j.physa.2004.02.056
Competition models are a fundamental paradigm in complex systems for the study of natural selection in different processes, from ecological competition to cultural diffusion and epidemic spreading. The interplay between diffusion and finite-range competition leads to relevant collective phenomena, such as pattern formation and wave fronts.
The inclusion of heterogeneity in the properties of the individuals (the "dispersal-structured populations") produces very interesting dynamics dominated by the faster or slower individuals, depending on the system parameters.
Influence of invasion on natural selection in dispersal-structured populations,
David Navidad Maeso, Marco Patriarca, Els Heinsalu,
Physica A 547, 124427 (2022),
doi: 0.1016/j.physa.2022.127389 arxiv.org/abs/2204.11899
The dynamics of natural selection in dispersal-structured populations,
Heinsalu, Els; Navidad Maeso, David; Patriarca, Marco,
Physica A 547 (2020) 124427 doi:0.1016/j.physa.2020.124427 arXiv:2004.14689
The role of dispersal in competition success and in the emerging diversity,
Els Heinsalu, David Navidad Maeso, and Marco Patriarca,
Eur. Phys. J. B 91, 255 (2018) doi:10.1140/epjb/e2018-90372-5 arXiv:2004.06088
The full shape of wealth distribution from small to large values of wealth has represented a challenge for economics since the time of the pioneering works of Pareto. The analogy between economic exchanges of wealth between economic agents and energy exchange between e.g. molecules of a fluid was originally suggested by Benoit Mandelbrot in the 60's but has been fully appreciated and worked out only starting at the end of the 90's. There is now a solid research line on the family of models referred to as "kinetic wealth exchange models" that shows how such models can take into account relevant economic sides as saving propensity/productivity, taxation, loans, behavioral traits, etc. to produce wealth distributions in excellent agreement with real data.
On the top of this, wealth-exchange models have provides an ideal framework for testing the general hypothesis of the role of noise and diversity underlying the origin of the observed power law distributions.
The microscopic origin of the Pareto law and other power-law distributions
M. Patriarca, E. Heinsalu, A. Chakraborti, and K. Kaski
in: Econophysics and Sociophysics: Recent Progress and Future Directions
F. Abergel et al. editors, Springer (2017), p. 159-176.
doi:10.1007/978-3-319-47705-3_12
Kinetic Exchange Models as D Dimensional Systems: A Comparison of Different Approaches
M. Patriarca, E Heinsalu, A Singh, A Chakraborti
in: Econophysics and Sociophysics: Recent Progress and Future Directions
F. Abergel et al. editors, Springer (2017), p 147-158.
doi:10.1007/978-3-319-47705-3_11
Previous version Thermal Equilibrium in D-dimensions: From Fluids and Polymers to Kinetic Wealth Exchange Models arxiv.org:1610.03367
Power-laws as statistical mixtures
M. Patriarca, E. Heinsalu, L. Marzola, A. Chakraborti, and K. Kaski
In: Proceedings of ECCS 2014: European Conference on Complex Systems, 271-282 (2016)
doi:10.1007/978-3-319-29228-1_23
Uni-vs. bi-directional kinetic exchange models
E. Heinsalu and M. Patriarca
International Journal of Computational Economics and Econometrics 5 (3), 213-219 (2015)
doi:10.1140/epjb/e2014-50270-6
RePEc:ids:ijcome:v:5:y:2015:i:3:p:213-219
Kinetic Wealth Exchange Models: A short review
M. Patriarca and E. Heinsalu
ICCSA20024 - The 4th International Conference on Complex Systems and Applications,
Normandie University, Le Havre, France - June 23-26 (2014)
Proceedings of ICCSA 2014, p.129-136
Kinetic models of immediate exchange
E. Heinsalu and M. Patriarca
The European Physical Journal B 87, 170 (2014)
doi:10.1140/epjb/e2014-50270-6
arxiv:1505.01274
M. Patriarca and A. Chakraborti
Kinetic exchange models: From molecular physics to social science
Am. J. Phys. 81, 618 (2013)
doi:10.1119/1.4807852
arXiv:1305.0768
A. Chakraborti, I.M. Toke, M. Patriarca, and F. Abergel
Econophysics review: I. Empirical facts, Quantitative Finance 11 (2011) 991-1012 doi:10.1080/14697688.2010.539248
Econophysics review: II. Agent-based models, Quantitative Finance 11 (2011) 1013-1041 doi:10.1080/14697688.2010.539249 arXiv:0909.1974
M. Patriarca, E. Heinsalu, R. Kitt, and J. Kalda
Econophysics studies in Estonia
Journal of Science and Culture (Indian Science News Association) 76(9-10) (2010) 374
Special issue Sep.-Oct. “Econophysics”
http://www.scienceandculture-isna.org/sep-oct-2010.htm
arXiv:1006.3708
M. Patriarca, E. Heinsalu, and A. Chakraborti
Basic kinetic wealth-exchange models: common features and open problems
Eur. Phys. J. B 73, (2010) 145
doi:10.1140/epjb/e2009-00418-6
arXiv:physics/06112452
A. Chakraborti and M. Patriarca
A variational principle for the Pareto power law
Phys. Rev. Lett. 103 (2009) 228701
doi:10.1103/PhysRevLett.103.228701
arXiv:cond-mat/0605325
A. Chakraborty and M. Patriarca
Gamma-distribution and wealth inequality
Pramana J. Phys. 71(2) (2008) 233
Special Issue: Statistical Physics Approaches to Multidisciplinary Problems
doi:10.1007/s12043-008-0156-3
https://www.ias.ac.in/describe/article/pram/071/02/0233-0243🔓
arXiv.org:0802.4410
M. Patriarca, A. Chakraborti, E. Heinsalu, and G. Germano
Relaxation in Statistical Many-agent Economy Models
Eur. Phys. J. B 57 (2007) 219
doi:10.1140/epjb/e2007-00122-7
arXiv:physics/0608174
M. Patriarca, A. Chakraborti, and G. Germano
Influence of saving propensity on the power-law tail of wealth distribution
Physica A 369 (2006) 723
doi:10.1016/j.physa.2006.01.091
arXiv:physics/0506028
M. Patriarca, A. Chakraborti, K. Kaski, and G. Germano
Kinetic theory models for the distribution of wealth: power law from overlap of exponentials
in: Econophysics of Wealth Distributions, Econophys-Kolkata 1, A. Chatterjee, S.Yarlagadda, B.K. Chakrabarti, Eds., Springer, 2005
doi:10.1007/88-470-0389-X_10
arXiv:physics/0504153
M. Patriarca, A. Chakraborti, and K. Kaski
Gibb’s versus non-Gibb’s distributions in money dynamics
Physica A 340 (2004) 334
doi:10.1016/j.physa.2004.04.024
arXiv:cond-mat/0312167
M. Patriarca, A. Chakraborti, and K. Kaski
A statistical model with a standard Γ-distribution
Phys. Rev. E 70, (2004) 016104
doi:10.1103/PhysRevE.70.016104
arXiv:cond-mat/0402200