1,299 research outputs found
Nash Equilibria in Games over Graphs Equipped with a Communication Mechanism
We study pure Nash equilibria in infinite-duration games on graphs, with partial visibility of actions but communication (based on a graph) among the players. We show that a simple communication mechanism consisting in reporting the deviator when seeing it and propagating this information is sufficient for characterizing Nash equilibria. We propose an epistemic game construction, which conveniently records important information about the knowledge of the players. With this abstraction, we are able to characterize Nash equilibria which follow the simple communication pattern via winning strategies. We finally discuss the size of the construction, which would allow efficient algorithmic solutions to compute Nash equilibria in the original game
On the linear convergence of distributed Nash equilibrium seeking for multi-cluster games under partial-decision information
This paper considers the distributed strategy design for Nash equilibrium
(NE) seeking in multi-cluster games under a partial-decision information
scenario. In the considered game, there are multiple clusters and each cluster
consists of a group of agents. A cluster is viewed as a virtual noncooperative
player that aims to minimize its local payoff function and the agents in a
cluster are the actual players that cooperate within the cluster to optimize
the payoff function of the cluster through communication via a connected graph.
In our setting, agents have only partial-decision information, that is, they
only know local information and cannot have full access to opponents'
decisions. To solve the NE seeking problem of this formulated game, a
discrete-time distributed algorithm, called distributed gradient tracking
algorithm (DGT), is devised based on the inter- and intra-communication of
clusters. In the designed algorithm, each agent is equipped with strategy
variables including its own strategy and estimates of other clusters'
strategies. With the help of a weighted Fronbenius norm and a weighted
Euclidean norm, theoretical analysis is presented to rigorously show the linear
convergence of the algorithm. Finally, a numerical example is given to
illustrate the proposed algorithm
On the Hardness of Signaling
There has been a recent surge of interest in the role of information in
strategic interactions. Much of this work seeks to understand how the realized
equilibrium of a game is influenced by uncertainty in the environment and the
information available to players in the game. Lurking beneath this literature
is a fundamental, yet largely unexplored, algorithmic question: how should a
"market maker" who is privy to additional information, and equipped with a
specified objective, inform the players in the game? This is an informational
analogue of the mechanism design question, and views the information structure
of a game as a mathematical object to be designed, rather than an exogenous
variable.
We initiate a complexity-theoretic examination of the design of optimal
information structures in general Bayesian games, a task often referred to as
signaling. We focus on one of the simplest instantiations of the signaling
question: Bayesian zero-sum games, and a principal who must choose an
information structure maximizing the equilibrium payoff of one of the players.
In this setting, we show that optimal signaling is computationally intractable,
and in some cases hard to approximate, assuming that it is hard to recover a
planted clique from an Erdos-Renyi random graph. This is despite the fact that
equilibria in these games are computable in polynomial time, and therefore
suggests that the hardness of optimal signaling is a distinct phenomenon from
the hardness of equilibrium computation. Necessitated by the non-local nature
of information structures, en-route to our results we prove an "amplification
lemma" for the planted clique problem which may be of independent interest
05361 Abstracts Collection -- Algorithmic Aspects of Large and Complex Networks
From 04.09.05 to 09.09.05, the Dagstuhl Seminar 05361 ``Algorithmic Aspects of Large and Complex Networks\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
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