Risk-Dominant Equilibrium in Quantum Prisoner's Dilemma

TL;DR

This paper explores how entanglement influences the selection of risk-dominant equilibrium in quantum prisoner's dilemma, showing that entanglement promotes cooperation and improves outcomes.

Contribution

It demonstrates that entanglement fully determines the risk-dominant equilibrium in the quantum prisoner's dilemma, highlighting its role in quantum game dynamics.

Findings

Entanglement controls the risk-dominant equilibrium.

Entanglement promotes quantum cooperation.

Improves outcome in the quantum prisoner's dilemma.

Abstract

The choice of a unique Nash equilibrium (NE) is crucial in theoretical classical and quantum games. The Eiswer-Wilkens-Lewenstein quantization scheme solves the prisoner's dilemma only for high entanglement. At medium entanglement, there are multiple NEs. We investigate the selection of a unique NE in the quantum prisoner's dilemma with variable dilemma strength parameters. The risk-dominance criterion is used. The influence of the dilemma strength parameters and entanglement is emphasized. We found that entanglement completely controls the risk-dominant equilibrium. Entanglement promotes quantum-cooperation in the risk-dominant equilibrium and thus improves its outcome.