The arrow of time in operational formulations of quantum theory

Abstract

The operational formulations of quantum theory are drastically time oriented. However, to the best of our knowledge, microscopic physics is time-symmetric. We address this tension by showing that the asymmetry of the operational formulations does not reflect a fundamental time-orientation of physics. Instead, it stems from built-in assumptions about the $users$ of the theory. In particular, these formalisms are designed for predicting the future based on information about the past, and the main mathematical objects contain implicit assumption about the past, but not about the future. The main asymmetry in quantum theory is the difference between knowns and unknowns.

16 pages + references, a few diagrams. This version is to appear in Quantum. Title has changed, it used to be "Quantum information and the arrow of time''

References in corpus (5)

• A Spin Entanglement Witness for Quantum Gravity
• Gravitationally-induced entanglement between two massive particles is sufficient evidence of quantum effects in gravity
• A derivation of quantum theory from physical requirements
• Symmetries of quantum evolutions
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• Relational Quantum Mechanics is about Facts, not States: A reply to Pienaar and Brukner
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• Axioms for retrodiction: achieving time-reversal symmetry with a prior
• A general framework for cyclic and fine-tuned causal models and their compatibility with space-time
• Inferring the arrow of time in quantum spatiotemporal correlations
• Experimental demonstration of input-output indefiniteness in a single quantum device
• Role of Dilations in Reversing Physical Processes: Tabletop Reversibility and Generalized Thermal Operations
• Entanglement, Complexity, and Causal Asymmetry in Quantum Theories
• Time-symmetry and topology of the Aharonov-Bohm effect
• Histories without collapse
• Origin of the Arrow of Time in Quantum Mechanics
• On the Time Orientation of Probabilistic Theories