2018/04/30 by Juan Diaz Dorronsoro, Jonathan J. Halliwell, J. J. Halliwell +4 · 3 citations
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Boundary (topology) #Boundary value problem #Classical mechanics #Cold Atom Physics and Bose-Einstein Condensates #Cosmology and Gravitation Theories #Mathematical analysis #Mathematics #Minisuperspace #Momentum (technical analysis) #Nonlinear system #Path integral formulation #Physics #Quantum cosmology #Quantum mechanics #Scale (ratio) #Semiclassical physics #State (computer science) #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevlett.121.081302
published as Phys. Rev. Lett. 121, 081302 (2018) · Dedicated to the memory of Stephen Hawking
openalex publication_date 2018/08/20 · arxiv created 2018/09/10 · arxiv updated 2018/09/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We evaluate the no-boundary path integral exactly in a Bianchi type IX minisuperspace with two scale factors. In this model the no-boundary proposal can be implemented by requiring one scale factor to be zero initially together with a judiciously chosen regularity condition on the momentum conjugate to the second scale factor. Taking into account the nonlinear backreaction of the perturbations we recover the predictions of the original semiclassical no-boundary proposal. In particular we find that large perturbations are strongly damped, consistent with vacuum state wave functions.