General Density Matrix Theory

Karl Blum

Karl Blum

Alexander Shalyt-Margolin, A. Ya. Tregubovich

It was shown that if in Quantum Theory a fundamental length exists, then in this case there is not pure states. It was noted, that theory satisfying General Uncertainty Relations (GUR) are related to the mentioned above theories. Moreover, the density matrix at the Planck scale can not be defined in the usual way, because in this case the density matrix trace is strongly less than 1. Then density matrix must be changed by its progenitrix or as we call it density pro-matrix, which at low energy limit turns to the density matrix. This transition corresponds to non-unitary one from Quantum Mechanics with GUR to Quantum mechanics. Below the implications of obtained results are enumerated. A new view on the Black Holes Information Paradox are discussed.

M. Roberts, W. E. Hagston

A general equation governing the time development of the diagonal part of the density matrix is proposed for weakly interacting systems possessing no off-diagonal long range order. This equation, which involves generalized Møller operators of the type employed in S-matrix theory, is solved for two cases and leads to the generalized Pauli and Boltzmann equations.

Jinshan Wu, Shouyong Pei

Density Matrix is used to unify the description of classical and quantum objects. The idea is that both states of classical object and states of quantum object can be regarded as vectors in Hilbert space, so that all the states can be represented by density matrices. After constructing the general framework, we apply this to discuss the possibility to map a quantum density matrix onto a classical density matrix, which is also the question explored in Hidden Variable Theory (HVT) of Quantum Mechanics (QM). Bell's Theorem set a boundary between HVT and QM, but the place of the real quantum world depends on experiments. However, here HVT is ruled out just by theoretical consideration. We tackle this question by explicitly constructing the most general HVT, which gives all desired results according QM, and then checking its validity and acceptability. Relation between such HVT and Bell's inequality and Kochen-Specker theorem is also discussed.

K. Husimi, Yoshihiro Kitano, Toshiyuki Nishiyama