Loops Rescue the No-Boundary Proposal

Martin Bojowald and Suddhasattwa Brahma
Phys. Rev. Lett. 121, 201301 – Published 13 November 2018
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Abstract

New and nontrivial properties of off-shell instantons in loop quantum cosmology show that dynamical signature change naturally cures recently observed problems in the semiclassical path integral of quantum gravity. If left unsolved, these problems would doom any theory of smooth initial conditions of the Universe. The no-boundary proposal, as a specific example of such a theory, is rescued by loops, presenting a rare instance of a fruitful confluence of different approaches to quantum cosmology.

  • Received 26 June 2018
  • Revised 28 September 2018

DOI:https://doi.org/10.1103/PhysRevLett.121.201301

© 2018 American Physical Society

Physics Subject Headings (PhySH)

Gravitation, Cosmology & Astrophysics

Authors & Affiliations

Martin Bojowald*

  • Institute for Gravitation and the Cosmos, The Pennsylvania State University, 104 Davey Lab, University Park, Pennsylvania 16802, USA

Suddhasattwa Brahma

  • Asia Pacific Center for Theoretical Physics, Pohang 37673, South Korea

  • *bojowald@gravity.psu.edu
  • suddhasattwa.brahma@gmail.com

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Issue

Vol. 121, Iss. 20 — 16 November 2018

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