|
In game theory, a game is said to be a potential game if the incentive of all players to change their strategy can be expressed using a single global function called the potential function. Robert W. Rosenthal created the concept of a congestion game in 1973. Dov Monderer and Lloyd Shapley 〔 〕 created the concept of a potential game and proved that every congestion game is a potential game. The properties of several types of potential games have since been studied. Games can be either ''ordinal'' or ''cardinal'' potential games. In cardinal games, the difference in individual payoffs for each player from individually changing one's strategy ''ceteris paribus'' has to have the same value as the difference in values for the potential function. In ordinal games, only the signs of the differences have to be the same. The potential function is a useful tool to analyze equilibrium properties of games, since the incentives of all players are mapped into one function, and the set of pure Nash equilibria can be found by locating the local optima of the potential function. Convergence and finite-time convergence of an iterated game towards a Nash equilibrium can also be understood by studying the potential function. ==Definition== We will define some notation required for the definition. Let be the number of players, the set of action profiles over the action sets of each player and be the payoff function. A game is: * an exact potential game if there is a function such that , :: ::That is: when player switches from action to action , the change in the potential equals the change in the utility of that player. * a weighted potential game if there is a function and a vector such that , :: * an ordinal potential game if there is a function such that , :: * a generalized ordinal potential game if there is a function such that , :: *a best-response potential game if there is a function such that , :: where is the best payoff for player given . 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Potential game」の詳細全文を読む スポンサード リンク
|