Martedì 7 marzo, ore 14:00,
Sala di Consiglio, Dipartimento di Matematica, Sapienza Università di Roma.
*Speaker: *Markus Fischer, Università di Padova
*Title: *On correlated equilibria and mean field games
*Abstract: *Mean field games are limit models for symmetric N-player games,
as the number of players N tends to infinity. The prelimit models are
usually solved in terms of Nash equilibria. A generalization of the notion
of Nash equilibrium, due to Robert Aumann (1974, 1987), is that of
correlated equilibrium. In a simple discrete setting, we will discuss
correlated equilibria for mean field games and their connection with the
underlying N-player games. We first consider equilibria in restricted
strategies (Markov open-loop), where control actions depend only on time
and a player's own state. In this case, N-player correlated equilibria are
seen to converge to the mean field game limit and, conversely, correlated
mean field game solutions induce approximate N-player correlated
equilibria. We then discuss the problem of constructing approximate
equilibria when deviating players have access to the aggregate system
state. We also give an explicit example of a correlated mean field game
solution not of Nash-type. Results (with L. Campi and Federico Cannerozzi)
on a related notion of equilibrium in a diffusion-type setting will be
mentioned as well.
Joint work with Ofelia Bonesini (Imperial College London) and Luciano Campi
(University of Milan "La Statale")