Approaching the Problem of Time with a Combined Semiclassical-Records-Histories Scheme

摘要: I approach the problem of time and other foundations quantum (QM) cosmology using a combined histories, timeless semiclassical approach. This is along lines pursued by Halliwell. It involves probabilities for dynamical trajectories entering regions configuration space, which are computed within regime. Moreover, objects that Halliwell uses in this commute with Hamiltonian constraint, H. has not hitherto been considered models also possess nontrivial linear constraints, Lin. paper carries out some concrete relational particle mechanics (RPMs). If there commutation Lin—the Kuchař observables condition—the constructed Dirac observables. shows explicitly resolved 1D 2D RPMs. Then as first route to Halliwell’s constraints construction observables, consider theories formally known, giving triangle an example. As second route, apply indirect method generalizes both group averaging Barbour’s best matching. For conceptual clarity, my study simpler case 2003 sharp-edged window function. leave elsewise-improved softened 2009 subsequent II. Finally, provide comments on how well it fares regards various facets implementation QM propositions.