This is a set of notes dedicated to the memory of Valery Rubakov who has inspired by his works the concept of the microcanonical density matrix of the Universe, which is likely to resolve the puzzles and inconsistencies of the known no-boundary and tunneling prescriptions for the cosmological wavefunction and suggests the existence of pre-inflationary thermal stage of the cosmological evolution with its UV bounded subplanckian energy scale.
No takes yet. Share an insight, caveat, or question.
A. O. Barvinsky (2024) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: