Phoenix, Arizona is a southwestern U.S. state.
In network theory , the Braunstein-Ghosh-Severini entropy -LRB- BGS entropy -RRB- of a network is the von Neumann entropy of a density matrix given by a normalized Laplacian matrix of the network .. network theory. network theory. von Neumann entropy. von Neumann entropy. density matrix. density matrix. Laplacian matrix. Laplacian matrix. This definition of entropy does not have a clear thermodynamical interpretation .. The BGS entropy has been used in the context of quantum gravity .. quantum gravity. quantum gravity