Interplay between theories of quantum and classical signals: classical representation of entanglement

Abstract

The idea that quantum mechanics (QM) is simply a version of classical field theory is very old. Recently this idea has been realized in a new mathematical framework - on the basis of theory of random fields (L₂-valued random variables). Surprisingly (for at least orthodox Copenhagenist) fundamental predictions of QM can be reproduced on the basis of a purely wave model (prequantum classical statistical field theory, PCSFT). In particular, all quantum correlations (including correlations of composite systems in entangled states) can be represented as correlations of classical random signals. These signals fluctuate at the space-time scale which is essentially finer than the scale of quantum measurements. At the moment we are not able to monitor such signals. However, one can expect that increasing of the precision of measurements will provide such a possibility. In this paper we show that bosonic and fermionic correlations can be obtained in the classical field framework. Finally, we stress that QM can be reduced to theory of classical random fields only in the presence of a relatively strong background field.