Entanglement and quantum strategies reduce congestion costs in Pigou networks

Pigou’s problem has many applications in real life scenarios like traffic networks, graph theory, data transfer in internet networks, etc. The two player classical Pigou’s network has an unique Nash equilibrium with the Price of Stability and Price of Anarchy agreeing with each other. The situation changes for the k person classical Pigou’s network with n being the total number of people. If we fix the behaviour of (n−2) people and assume that k persons take path P2 where k<(n−2) and the remaining take path P1, the minimum cost of Nash equilibrium becomes k dependent and we find a particular k for which the cost is an absolute minimum. In contrast to the two person classical Pigou’s network, the quantum two qubit Pigou’s network with maximal entanglement gives a lower cost for the Nash equilibrium. In contrast to k person classical Pigou’s network, its quantum version with the quantum miracle move strategy M has reduced cost for the Nash equilibrium. This has major implications for information transfer in both classical as well as quantum data networks. By employing entanglement and quantum strategies, one can significantly reduce congestion costs in quantum data networks.