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This study explores key concepts in game dynamics, focusing on the Hawk-Dove game, generalized replicator equations, and the rock-paper-scissors game. It examines interactions in bi-matrix games, including the Hawk-Dove-Retaliator and Hawk-Dove-Bully models. The analysis includes payoff matrices, equilibrium points, and local stability in evolutionary strategies, highlighting how tactics evolve in populations competing for resources. The findings contribute to understanding aggressiveness and behavioral strategies in ecological contexts.
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Introduction to game dynamics Pierre Auger IRD UR Geodes, Centre d’île de France et Institut Systèmes Complexes, ENS Lyon
Summary • Hawk-dove game • Generalized replicator equations • Rock-cissor-paper game • Hawk-dove-retaliator and hawk-dove-bully • Bi-matrix games
Fighting for resources Dominique Allainé, Lyon 1
Hawk-Dove game • Payoff matrix • Gain • Cost
Playing against a population • Hawk reward • Dove reward • Average reward
Replicator equations With
Replicator equations then Because Leading to
Replicator equations • G<C, dimorphic equilibrium • G>C, pure hawk equilibrium J. Hofbauer & K. Sigmund, 1988 Butterflies
Replicator equations : n tactics (n>2) • Payoff matrix • aij reward when playing i against j
Replicator equations With • Reward player i • Average reward
Equilibrium With • Corner • Unique interior equilibrium (linear)
Rock-Scissor-Paper game • Payoff matrix
Four equilibrium points • Unique interior equilibrium
Local stability analysis saddle • Unique interior equilibrium center
R-C-P phase portrait • First integral
Hawk-Dove-Retaliator game • Payoff matrix
Hawk-Dove-Bully game • Payoff matrix
Bimatrix games (two populations) • Pop 1 against pop 2 • Pop 2 against pop 1
Bimatrix games (2 tactics) • Reward player i • Average reward
Adding any column of constant terms • Pop 1 against pop 2 • Pop 2 against pop 1
Five equilibrium points • Unique interior equilibrium (possibility)
Local stability analysis • Corners (Stable or unstable nodes, saddle) • Unique interior equilibrium (trJ=0 ; center, saddle)
Battle of the sexes • Females : Fast (Fa) or coy (Co) • Males : Faithful (F) or Unfaithful (UF)
Battle of the sexes • Males against females
Battle of the sexes • Females against males
Five equilibrium points • Unique interior equilibrium : C<G<T+C/2
Local stability analysis (center) • Existence of a first integral H(x,y) :