Arrow of time and quantum physics

TL;DR

This paper explores the fundamental nature of the arrow of time in quantum physics, discussing its implications for spacetime symmetries, quantum information loss, and the emergence of quantum frameworks from classical constraints.

Contribution

It demonstrates how the arrow of time can be integrated into quantum physics through semi-group actions, addresses ambiguities with massless excitations, and links classical operations to quantum theory.

Findings

Semi-group action of time extends to spacetime translations in Minkowski space.

Ambiguities arise in time translation extensions with massless excitations.

Loss of quantum information on states is characterized by the theory.

Abstract

Based on the hypothesis that the (non-reversible) arrow of time is intrinsic in any system, no matter how small, the consequences are discussed. Within the framework of local quantum physics it is shown how such a semi-group action of time can consistently be extended to that of the group of spacetime translations in Minkowski space. In presence of massless excitations, however, there arise ambiguities in the theoretical extensions of the time translations to the past. The corresponding loss of quantum information on states upon time is determined. Finally, it is explained how the description of operations in classical terms combined with constraints imposed by the arrow of time leads to a quantum theoretical framework. These results suggest that the arrow of time is fundamental in nature and not merely a consequence of statistical effects on which the Second Law is based.