5,585 research outputs found
An Optimal Control Derivation of Nonlinear Smoothing Equations
The purpose of this paper is to review and highlight some connections between
the problem of nonlinear smoothing and optimal control of the Liouville
equation. The latter has been an active area of recent research interest owing
to work in mean-field games and optimal transportation theory. The nonlinear
smoothing problem is considered here for continuous-time Markov processes. The
observation process is modeled as a nonlinear function of a hidden state with
an additive Gaussian measurement noise. A variational formulation is described
based upon the relative entropy formula introduced by Newton and Mitter. The
resulting optimal control problem is formulated on the space of probability
distributions. The Hamilton's equation of the optimal control are related to
the Zakai equation of nonlinear smoothing via the log transformation. The
overall procedure is shown to generalize the classical Mortensen's minimum
energy estimator for the linear Gaussian problem.Comment: 7 pages, 0 figures, under peer reviewin
Evolutionary dynamics in heterogeneous populations: a general framework for an arbitrary type distribution
A general framework of evolutionary dynamics under heterogeneous populations
is presented. The framework allows continuously many types of heterogeneous
agents, heterogeneity both in payoff functions and in revision protocols and
the entire joint distribution of strategies and types to influence the payoffs
of agents. We clarify regularity conditions for the unique existence of a
solution trajectory and for the existence of equilibrium. We confirm that
equilibrium stationarity in general and equilibrium stability in potential
games are extended from the homogeneous setting to the heterogeneous setting.
In particular, a wide class of admissible dynamics share the same set of
locally stable equilibria in a potential game through local maximization of the
potential
Mean field games based on the stable-like processes
In this paper, we investigate the mean field games with K classes of agents who are weakly coupled via the empirical measure. The underlying dynamics of the representative agents is assumed to be a controlled nonlinear Markov process associated with rather general integro-differential generators of LĀ“evy-Khintchine type (with variable coefficients), with the major stress on applications to stable and stable- like processes, as well as their various modifications like tempered stable-like processes or their mixtures with diffusions. We show that nonlinear measure-valued kinetic equations describing the dynamic law of large numbers limit for system with large number N of agents are solvable and that their solutions represent 1/N-Nash equilibria for approximating systems of N agents
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