BEGIN:VCALENDAR VERSION:2.0 PRODID:-//wp-events-plugin.com//6.4.7.2//EN TZID:Europe/Paris X-WR-TIMEZONE:Europe/Paris BEGIN:VEVENT UID:0-983@lptms.universite-paris-saclay.fr DTSTART;TZID=Europe/Paris:20241216T100000 DTEND;TZID=Europe/Paris:20241216T130000 DTSTAMP:20241206T135108Z URL:http://www.lptms.universite-paris-saclay.fr/seminars/soutenance-de-the se-louis-bremaud/ SUMMARY:Soutenance de thèse : Louis Bremaud - Petit amphi\, bâtiment Pasc al n° 530 - 16 Déc 24 10:00 DESCRIPTION:Mean Field Game description of virus propagation\n \;\nThis thesis investigates the role of human behavior in epidemic modeling. Epid emics are influenced by both individuals’ spontaneous responses and gove rnment-imposed measures\, creating a feedback loop that shapes the outbrea k's progression. However\, many existing models treat human behavior as an external factor\, limiting their realism. To address this gap\, the thesi s applies the Mean Field Game (MFG) framework\, a theoretical tool for inc orporating individual decision-making into epidemic models.\nThe first par t of the thesis applies the MFG approach to an SIR (Susceptible-Infected-R ecovered) model with a social structure. Individuals balance infection ris k against the social and economic costs of reducing contact. Numerical sim ulations with realistic parameters identify a Nash equilibrium\, reflectin g self-interested behavior\, and we compare it to the social optimum\, whi ch minimizes overall societal costs. The gap between these scenarios is na rrowed through constrained Nash equilibria\, which include government inte rventions. The analysis also reveals that changes in population size or mo del duration can lead to phase transitions in optimal strategies\, emphasi zing the need for adaptive policies.\nIn the second part\, the MFG framewo rk is extended to complex networks\, where individuals differ in connectiv ity. Using pairwise approximation\, we derive epidemic dynamics and integr ate MFG principles. Simulations on realistic contact networks highlight ho w variations in social cost structures influence individual behavior\, wit h significant differences observed based on connectivity levels. A related project provides new analytical insights into the SIR model on regular ne tworks.\n\n\nJury : Alain Barrat (examinateur)\, Marc Barthelemy (préside nt du Jury)\, Laura di Domenico (examinatrice)\, Olivier Giraud (co-direct eur de thèse)\, Sergio Gomez (rapporteur)\, Gabriel Turinici (rapporteur) \, Denis Ullmo (directeur de thèse)\n\n\n\n CATEGORIES:seminars LOCATION:Petit amphi\, bâtiment Pascal n° 530\, rue André Rivière\, Ors ay\, 91405\, France X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=rue André Rivière\, Orsay \, 91405\, France;X-APPLE-RADIUS=100;X-TITLE=Petit amphi\, bâtiment Pasca l n° 530:geo:0,0 END:VEVENT BEGIN:VTIMEZONE TZID:Europe/Paris X-LIC-LOCATION:Europe/Paris BEGIN:STANDARD DTSTART:20241027T020000 TZOFFSETFROM:+0200 TZOFFSETTO:+0100 TZNAME:CET END:STANDARD END:VTIMEZONE END:VCALENDAR