1997/08/31 by Robert B. Griffiths · 180 citations
Computer Science · Mathematics · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Computer science #Consistent histories #Epistemology #Granularity #Hilbert space #Mathematics #Philosophy #Physicist #Physics #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum dynamics #Quantum mechanics #Quantum process #Relational quantum mechanics #Space (punctuation) #Statistical physics #Theoretical physics #quant-ph
paper · pdf · doi:10.1103/physreva.57.1604
published in Physical Review A 57(3), 1604-1618 (American Physical Society) · Minor revisions to bring into conformity with published version. Revtex 29 pages including 1 page with figures
openalex publication_date 1998/03/01 · arxiv created 1998/12/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In consistent-history quantum theory, a description of the time development of a quantum system requires choosing a framework or consistent family, and then calculating probabilities for the different histories that it contains. It is argued that the framework is chosen by the physicist constructing a description of a quantum system on the basis of questions he wishes to address, in a manner analogous to choosing a coarse-graining of the phase space in classical statistical mechanics. The choice of framework is not determined by some law of nature, though it is limited by quantum incompatibility, a concept that is discussed using a two-dimensional Hilbert space (spin half particle). Thus certain questions of physical interest can only be addressed using frameworks in which they make (quantum-mechanical) sense. The physicist's choice does not influence reality, nor does the presence of choices render the theory subjective. On the contrary, predictions of the theory can, in principle, be verified by experimental measurements. These considerations are used to address various criticisms and possible misunderstandings of the consistent-history approach, including its predictive power, whether it requires a new logic, whether it can be interpreted realistically, the nature of ``quasiclassicality,'' and the possibility of ``contrary'' inferences.