2002/12/04 by Asher Peres, Daniel R. Terno · 1 voice · 4 citations
Computer Science · Physics and Astronomy · #General relativity #Noncommutative and Quantum Gravity Theories #Physics #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum gravity #Quantum mechanics #Special relativity #Theoretical physics #Theory of relativity #gr-qc #hep-th #quant-ph
paper · pdf · doi:10.1103/revmodphys.76.93
published as Rev.Mod.Phys.76:93-123,2004 · 32 pages RevTeX4,4 figures, submitted to RMP. Some parts of the text deleted, many others substantially expanded and updated. One figure and two appendices added. Many new references
arxiv published 2002/12/04 · arxiv created 2003/07/07 · arxiv updated 2003/07/07 · openalex publication_date 2004/01/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
This article discusses the intimate relationship between quantum mechanics, information theory, and relativity theory. Taken together these are the foundations of present-day theoretical physics, and their interrelationship is an essential part of the theory. The acquisition of information from a quantum system by an observer occurs at the interface of classical and quantum physics. The authors review the essential tools needed to describe this interface, i.e., Kraus matrices and positive-operator-valued measures. They then discuss how special relativity imposes severe restrictions on the transfer of information between distant systems and the implications of the fact that quantum entropy is not a Lorentz-covariant concept. This leads to a discussion of how it comes about that Lorentz transformations of reduced density matrices for entangled systems may not be completely positive maps. Quantum field theory is, of course, necessary for a consistent description of interactions. Its structure implies a fundamental tradeoff between detector reliability and localizability. Moreover, general relativity produces new and counterintuitive effects, particularly when black holes (or, more generally, event horizons) are involved. In this more general context the authors discuss how most of the current concepts in quantum information theory may require a reassessment.