Dottore di ricerca

ciclo: XXXVI

Titolo della tesi: Modeling Complex Digital Systems

This dissertation applies Complexity Science to the study of digital environments, emphasizing the effects of recommendation algorithms and the development of agent-based models augmented by Large Language Models (LLMs). The thesis begins by examining power laws in complex systems, discussing their mathematical properties, connections to Heaps' law and Zipf's law, and implications for understanding phenomena like Black Swans and extreme events. Also network theory is revisited and special attention is given to bipartite networks, crucial for the analysis of recommendation algorithms. A large part of the thesis is devoted to the role of recommendation algorithms in online social systems, encompassing a literature review of their effects on inequality, opinion polarization, and echo chamber formation. This is complemented by a detailed analysis of opinion dynamics models influenced by recommendation algorithms and a study of user-user collaborative filtering. On one hand, our results show that recommendation algorithm may fundamentally alter social dynamics in large groups, inducing opinion polarization. However, mathematical models can be used to limit this drawback and to understand how to use these algorithms to improve users' content consumption. As final topic, the Thesis covers the latest advancements in AI, particularly LLMs, and their applications in social sciences. It discusses the concept of generative agents and their potential in simulating online social environments and testing platform interventions. This includes a model of network growth based on generative agents demonstrating emergent scale-free structures and linear preferential attachment among them. Such a finding is a first step in replicating online social environment using in silico LLMs powered simulations.

Produzione scientifica

11573/1692557 - 2023 - Effect of collaborative-filtering-based recommendation algorithms on opinion polarization
Bellina, Alessandro; Castellano, Claudio; Pineau, Paul; Iannelli, Giulio; De Marzo, Giordano - 01a Articolo in rivista
rivista: PHYSICAL REVIEW. E (Ridge, NY: American Physical Society, [2016]-) pp. 1-17 - issn: 2470-0045 - wos: WOS:001149221000006 (0) - scopus: 2-s2.0-85176563622 (1)

11573/1672551 - 2023 - Effect of spatial correlations on Hopfield Neural Network and Dense Associative Memories
De Marzo, Giordano; Iannelli, Giulio - 01a Articolo in rivista
rivista: PHYSICA. A (Elsevier BV:PO Box 211, 1000 AE Amsterdam Netherlands:011 31 20 4853757, 011 31 20 4853642, 011 31 20 4853641, EMAIL:, INTERNET:, Fax: 011 31 20 4853598) pp. - - issn: 0378-4371 - wos: WOS:000976275300001 (0) - scopus: 2-s2.0-85146419788 (0)

11573/1692538 - 2023 - Mapping non-axisymmetric velocity fields of external galaxies
Sylos Labini, F.; Straccamore, M.; De Marzo, G.; Comer('O)N, S. - 01a Articolo in rivista
rivista: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY. LETTERS (Oxford : Blackwell) pp. 1560-1600 - issn: 1745-3925 - wos: WOS:001027921200006 (0) - scopus: 2-s2.0-85165918489 (1)

11573/1617838 - 2022 - The emergence of a concept in shallow neural networks
Agliari, Elena; Alemanno, Francesco; Barra, Adriano; De Marzo, Giordano - 01a Articolo in rivista
rivista: NEURAL NETWORKS (Elsevier Science Limited:Oxford Fulfillment Center, PO Box 800, Kidlington Oxford OX5 1DX United Kingdom:011 44 1865 843000, 011 44 1865 843699, EMAIL:,, INTERNET:,, Fax: 011 44 1865 843010) pp. 232-253 - issn: 0893-6080 - wos: WOS:000787889400020 (14) - scopus: 2-s2.0-85124273327 (19)

11573/1672556 - 2022 - Quantifying the unexpected: A scientific approach to Black Swans
De Marzo, Giordano; Gabrielli, Andrea; Zaccaria, Andrea; Pietronero, Luciano - 01a Articolo in rivista
rivista: PHYSICAL REVIEW RESEARCH (College Park MD: American Physical Society) pp. - - issn: 2643-1564 - wos: WOS:000843074700001 (1) - scopus: 2-s2.0-85135929155 (2)

11573/1672554 - 2022 - Filter bubble effect in the multistate voter model
Iannelli, G.; De Marzo, G.; Castellano, C. - 01a Articolo in rivista
rivista: CHAOS (Woodbury NY: American Institute of Physics, 1991-) pp. - - issn: 1054-1500 - wos: WOS:000788724700001 (4) - scopus: 2-s2.0-85128836419 (5)

11573/1672559 - 2022 - Modeling innovation in the cryptocurrency ecosystem
Marzo, Giordano De; Pandolfelli, Francesco; Servedio, Vito D P - 01a Articolo in rivista
rivista: SCIENTIFIC REPORTS (London: Springer Nature London: Nature Publishing Group) pp. 12942- - issn: 2045-2322 - wos: WOS:000833071900024 (10) - scopus: 2-s2.0-85135152590 (12)

11573/1484923 - 2021 - Dynamical approach to Zipf's law
De Marzo, Giordano; Gabrielli, Andrea; Zaccaria, Andrea; Pietronero, Luciano - 01a Articolo in rivista
rivista: PHYSICAL REVIEW RESEARCH (College Park MD: American Physical Society) pp. - - issn: 2643-1564 - wos: WOS:000612216700003 (17) - scopus: 2-s2.0-85103863800 (19)

11573/1619578 - 2021 - Zipf’s law for cosmic structures: How large are the greatest structures in the universe?
De Marzo, Giordano; Sylos Labini, Francesco; Pietronero, Luciano - 01a Articolo in rivista
rivista: ASTRONOMY & ASTROPHYSICS (Les Ulis: EDP Sciences, 2001- Berlin; Heidelberg; New York: Springer, 1969-2000) pp. - - issn: 0004-6361 - wos: WOS:000680492500001 (9) - scopus: 2-s2.0-85111781903 (9)

11573/1463704 - 2020 - Tolerance versus synaptic noise in dense associative memories
Agliari, Elena; De Marzo, Giordano - 01a Articolo in rivista
rivista: THE EUROPEAN PHYSICAL JOURNAL PLUS (Heidelberg ; Berlin : Springer) pp. - - issn: 2190-5444 - wos: WOS:000590617400001 (12) - scopus: 2-s2.0-85094972389 (14)

11573/1475262 - 2020 - Emergence of polarization in a voter model with personalized information
De Marzo, Giordano; Zaccaria, Andrea; Castellano, Claudio - 01a Articolo in rivista
rivista: PHYSICAL REVIEW RESEARCH (College Park MD: American Physical Society) pp. - - issn: 2643-1564 - wos: WOS:000605398300002 (13) - scopus: 2-s2.0-85107475132 (18)

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