On the geometry of no-boundary instantons in loop quantum cosmology

Abstract

We study the geometry of Euclidean instantons in loop quantum cosmology (LQC) such as those relevant for the no-boundary proposal. Confining ourselves to the simplest case of a cosmological constant in minisuperspace cosmologies, we analyze solutions of the semiclassical (Euclidean) path integral in LQC. We find that the geometry of LQC instantons have the peculiar feature of an infinite tail which distinguishes them from Einstein gravity. Moreover, due to quantum-geometry corrections, the small-a behaviour of these instantons seem to naturally favor a closing-off of the geometry in a regular fashion as was originally proposed for the no-boundary wavefunction.

21 pages, comments welcome

References in corpus (8)

• Quantum cosmology: a review
• The Real No-Boundary Wave Function in Lorentzian Quantum Cosmology
• Tunneling wave function of the universe
• Damped perturbations in the no-boundary state
• Spherically symmetric canonical quantum gravity
• Loops rescue the no-boundary proposal
• The no-boundary wave function for loop quantum cosmology
• Path Integral and Effective Hamiltonian in Loop Quantum Cosmology

Cited by in corpus (2)

• Annihilation-to-nothing: DeWitt boundary condition inside a black hole
• Fuzzy instantons in landscape and swampland: review of the Hartle-Hawking wave function and several applications