A system of N interacting bosons can be regarded as a Bose-Einstein condensate if the single particle this has one eigenvalue of order N and all the others of order 1. Banks, Peskin, and Susskind showed that if it obeys an equation more general than Schr?dinger's, as suggested by Hawking, locality or energy conservation would be violated. The von Neumann entropy is minus the trace of this matrix times its logarithm. If and only if it is equal to its own square, it represents a pure state and could be alternately represented simply as a wavefunction. For 10 points, what is this mathematical description of general mixed states in quantum mechanics, with a name that evokes its use as a measure of the amount of "weight" of wave function per "vo
A system of N interacting bosons can be regarded as a Bose-Einstein condensate if the single particle this has one eigenvalue of order N and all the others of order 1. Banks, Peskin, and Susskind showed that if it obeys an equation more general than Schr?dinger's, as suggested by Hawking, locality or energy conservation would be violated. The von Neumann entropy is minus the trace of this matrix times its logarithm. If and only if it is equal to its own square, it represents a pure state and could be alternately represented simply as a wavefunction. For 10 points, what is this mathematical description of general mixed states in quantum mechanics, with a name that evokes its use as a measure of the amount of "weight" of wave function per "volume" of configuration space?
A system of N interacting bosons can be regarded as a Bose-Einstein condensate
density matrix