2021/03/15 by James B. Hartle, Hartle, James B.
Medicine · Physics and Astronomy · #Biofield Effects and Biophysics #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th) #Quantum Mechanics and Applications #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2103.08574
openalex publication_date 2021/03/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In a fundamental formulation of the quantum mechanics of a closed system such\nas the universe as a whole, three forms of information are needed to make\npredictions for the probabilities of alternative time histories of the closed\nsystem . These are the action functional of the elementary particles, the\nquantum istate of the universe, and the description of our specific history. We\ndiscuss the origin of the "quasiclassical realm" of familiar experience and\nHamiltonian quantum mechanics with its preferred time in such a formulation of\nquantum cosmology. It is argued that these features of the universe are not\ngeneral properties of quantum theory, but rather approximate features that are\nemergent after the Planck time as a consequence of theories of the closed\nsystem's quantum state and dynamics.\n