The Objective Past of a Quantum Universe: Redundant Records of Consistent Histories

Abstract

Motivated by the advances of quantum Darwinism and recognizing the role played by redundancy in identifying the small subset of quantum states with resilience characteristic of objective classical reality, we explore the implications of redundant records for consistent histories. The consistent histories formalism is a tool for describing sequences of events taking place in an evolving closed quantum system. A set of histories is consistent when one can reason about them using Boolean logic, i.e., when probabilities of sequences of events that define histories are additive. However, the vast majority of the sets of histories that are merely consistent are flagrantly non-classical in other respects. This embarras de richesses (known as the set selection problem) suggests that one must go beyond consistency to identify how the classical past arises in our quantum Universe. The key intuition we follow is that the records of events that define the familiar objective past are inscribed in many distinct systems, e.g., subsystems of the environment, and are accessible locally in space and time to observers. We identify histories that are not just consistent but redundantly consistent using the partial-trace condition introduced by Finkelstein as a bridge between histories and decoherence. The existence of redundant records is a sufficient condition for redundant consistency. It selects, from the multitude of the alternative sets of consistent histories, a small subset endowed with redundant records characteristic of the objective classical past. The information about an objective history of the past is then simultaneously within reach of many, who can independently reconstruct it and arrive at compatible conclusions in the present.

Further elaboration on the mathematical definition of a record was added. Final published version. 18 pages

References in corpus (18)

• Quantum Darwinism
• Consciousness as a State of Matter
• Quantum origins of objectivity
• A simple example of "Quantum Darwinism": Redundant information storage in many-spin environments
• Quantum origin of quantum jumps: Breaking of unitary symmetry induced by information transfer and the transition from quantum to classical
• Quantum Darwinism in a hazy environment
• Quantum Darwinism in quantum Brownian motion: the vacuum as a witness
• Quasiclassical Coarse Graining and Thermodynamic Entropy
• Objectivity in the Photonic Environment Through State Information Broadcasting
• Quantum Darwinism, Classical Reality, and the Randomness of Quantum Jumps
• The Rise and Fall of Redundancy in Decoherence and Quantum Darwinism
• A Solution to the Lorentzian Quantum Reality Problem
• Amplification, Redundancy, and the Quantum Chernoff Information
• The New Quantum Logic
• Amplification, Decoherence, and the Acquisition of Information by Spin Environments
• Entanglement Symmetry, Amplitudes, and Probabilities: Inverting Born's Rule
• Probability in decoherent histories
• Quantum probabilities from combination of Zurek's envariance and Gleason's theorem

Cited by in corpus (35)

• Quantum Decoherence
• Variational Consistent Histories as a Hybrid Algorithm for Quantum Foundations
• Quantum Theory of the Classical: Einselection, Envariance, Quantum Darwinism and Extantons
• Quantum Theory of the Classical: Quantum Jumps, Born's Rule, and Objective Classical Reality via Quantum Darwinism
• Eavesdropping on the Decohering Environment: Quantum Darwinism, Amplification, and the Origin of Objective Classical Reality
• Amplification, Decoherence, and the Acquisition of Information by Spin Environments
• Eliminating Ensembles from Equilibrium Statistical Physics: Maxwell's Demon, Szilard's Engine, and Thermodynamics via Entanglement
• Locality from the Spectrum
• Understanding quantum mechanics: a review and synthesis in precise language
• Does it Make Sense to Speak of Self-Locating Uncertainty in the Universal Wave Function? Remarks on Sebens and Carroll
• Classical branch structure from spatial redundancy in a many-body wavefunction
• Quantum Reversibility Is Relative, Or Do Quantum Measurements Reset Initial Conditions?
• Classicality with(out) decoherence: Concepts, relation to Markovianity, and a random matrix theory approach
• First Principles Numerical Demonstration of Emergent Decoherent Histories
• Timelessness strictly inside the Quantum Realm
• Emergent classicality in general multipartite states and channels
• Einselection, Equilibrium and Cosmology
• The consistent histories approach to loop quantum cosmology
• Quantum gravity in timeless configuration space
• Finite-Time Optimization of Quantum Szilard heat engine
• Emergence of Objectivity for Quantum Many-Body Systems
• Wavefunction branching: when you can't tell pure states from mixed states
• Objectivity in quantum measurement
• Decoherence: From Interpretation to Experiment
• The Autodidactic Universe
• Decoherence of Histories: Chaotic Versus Integrable Systems
• Classical branches and entanglement structure in the wavefunction of cosmological fluctuations
• On the relation between quantum Darwinism and approximate quantum Markovianity
• Emergence of outcomes in quantum mechanics
• Decoherent Histories Quantum Mechanics Starting with Records of What Happens
• Einselection from incompatible decoherence channels
• Contrary Inferences for Classical Histories within the Consistent Histories Formulation of Quantum Theory
• Environment-Assisted Shortcuts to Adiabaticity
• Emergence of non-Markovian Decoherent Histories in Integrable Environment: A "Tape Recorder" Model for Local Quantum Observables
• Wavefunction branches demand a definition!