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Rescue of Recombinant Newcastle Disease Virus from cDNA

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Published on: October 11, 2013

Loops Rescue the No-Boundary Proposal.

Martin Bojowald¹, Suddhasattwa Brahma²

¹Institute for Gravitation and the Cosmos, The Pennsylvania State University, 104 Davey Lab, University Park, Pennsylvania 16802, USA.

Physical Review Letters

|December 1, 2018

Summary

This summary is machine-generated.

Off-shell instantons in loop quantum cosmology reveal new properties that fix problems in quantum gravity

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Area of Science:

Cosmology
Quantum Gravity
Theoretical Physics

Background:

The semiclassical path integral in quantum gravity faces challenges with smooth initial conditions for the Universe.
The no-boundary proposal, a theory for the Universe's origin, is particularly affected by these issues.

Purpose of the Study:

To investigate off-shell instantons in loop quantum cosmology.
To address and resolve problems in the semiclassical path integral of quantum gravity.
To rescue theories of smooth initial conditions, such as the no-boundary proposal.

Main Methods:

Analysis of off-shell instantons within the framework of loop quantum cosmology.
Exploring the concept of dynamical signature change.
Applying these findings to the no-boundary proposal.

Main Results:

New, nontrivial properties of off-shell instantons were discovered.
Dynamical signature change was identified as a natural solution to the observed problems.
The no-boundary proposal was successfully rescued by loop quantum cosmology.

Conclusions:

Off-shell instantons in loop quantum cosmology offer a robust solution to fundamental problems in quantum gravity.
Dynamical signature change is a key mechanism for ensuring the validity of semiclassical path integrals.
This work demonstrates a successful integration of different quantum cosmology approaches, particularly benefiting the no-boundary proposal.