English

A Measure of Classicality

General Relativity and Quantum Cosmology 2021-04-30 v1 Cosmology and Nongalactic Astrophysics High Energy Physics - Theory

Abstract

A striking feature of our fundamentally indeterministic quantum universe is its quasiclassical realm -- the wide range of time place and scale in which the deterministic laws of classical physics hold. Our quasiclassical realmis an emergent feature of the fundamental theories of our universe's quantum state and dynamics. There are many types of quasiclassical realms our Universe could exhibit characterized by different variables, different levels of coarse-graining, different locations in spacetime, different classical physics, and different levels of classicality.We propose a measure of classicality for quasiclassical realms, We speculate on the observable consequences of different levels of classicality especially for information gathering and utilizing systems (IGUSes) such ourselves as observers of the Universe.

Keywords

Cite

@article{arxiv.2104.14465,
  title  = {A Measure of Classicality},
  author = {James B. Hartle and Murray Gell-Mann},
  journal= {arXiv preprint arXiv:2104.14465},
  year   = {2021}
}

Comments

9 pages, revtex4. arXiv admin note: substantial text overlap with arXiv:gr-qc/9509054

R2 v1 2026-06-24T01:38:26.427Z