Conference announcement: 30 Years of Game Theory at Institut Henri Poincaré, October 06-10, 2025, Paris.

Welcome

The Séminaire parisien de Théorie des Jeux is an open, inter-institutional, multi-disciplined seminar which covers all fields of game theory. It takes place on Monday from 11:00 to 12:00 am at Institut Henri Poincaré, 11 rue Pierre et Marie Curie, Paris 5ème. MAP

You will find the program for the current academic year on the page 2025/2026 and the program for past years on the page Archives.

The junior seminar welcomes PhD students in game theory to present their work.  You will find the program for the current academic year on the page Junior Seminar 2025/2026.

Next seminar:  

June 29, 2026 (room Maryam Mirzakhani): 

Felipe GARRIDO LUCERO (Université Toulouse Capitole)

Title : Prophet Inequalities with Delayed and Uncertain Acceptance (with Umberto GRANDI and Emile MARTINEZ)

Abstract : We introduce the prophet inequality with delayed and uncertain acceptance, a variant of the classical prophet inequality in which a decision maker sequentially evaluates options whose selection may fail and whose outcome is revealed only after a fixed delay. At each time step, the decision maker observes the realized value of an arriving option and must irrevocably decide whether to attempt to select it or to continue searching. If an option is selected, the process is suspended for a fixed delay period during which no other options can be considered. Once the delay expires, the selection succeeds with a known probability, in which case the decision maker receives the realized value and the process terminates; otherwise, the search resumes. We show that the decision maker can always guarantee a constant fraction of the utility achieved by the Prophet, an omniscient benchmark that knows all future realizations in advance. In the limiting case where acceptance outcomes are revealed immediately, our guarantee recovers the classical 1/2 bound. This setting also gives rise to a second natural benchmark: the value-aware decision maker, who knows all future value realizations in advance but not the acceptance outcomes. We characterize the worst-case competitive ratios among all three agents and show that they all coincide with 1/2. Finally, we provide sufficient conditions under which the value-aware decision maker surpasses the 1/2 barrier against the more informed Prophet, namely when all acceptance probabilities are strictly positive, by establishing a reduction to a classical prophet inequality instance over scaled Bernoulli random variables.

Organizers

Frédéric Koessler (CNRS, HEC Paris), frederic.koessler[at]gmail[dot]com

Maël Le Treust  (CNRS,  IRISA Rennes), mael.le-treust[at]cnrs[dot]fr

Chantal Marlats (LEMMA, Université Paris Panthéon-Assas), chantal.marlats[at]u-paris2[dot]fr

Yannick Viossat (CEREMADE, PSL), viossat[at]ceremade[dot]dauphine[dot]fr

To join (or unsuscribe from) our mailing list, please contact Maël Le Treust at mael.le-treust[at]cnrs[dot]fr. 

Former organizers

Joseph Abdou; Bernard De Meyer; Françoise Forges; Olivier Gossner;  Marie Laclau; Rida Laraki; Lucie Ménager; Vianney Perchet; Jérôme Renault; Dinah Rosenberg; Sylvain Sorin; Tristan Tomala; Xavier Venel; Nicolas Vieille; Guillaume Vigeral; Bruno Ziliotto