Quantum geometry and effective dynamics of Janis-Newman-Winicour singularities

TL;DR

This paper extends loop quantum gravity techniques to the Janis-Newman-Winicour spacetime, incorporating a scalar field, and develops an effective quantum dynamics that resolves singularities while matching classical behavior at low curvature.

Contribution

It introduces a novel effective quantum dynamics for the JNW spacetime with two regularization parameters, ensuring singularity resolution and classical correspondence.

Findings

Singularity resolution in JNW spacetime

Effective dynamics matches classical at low curvature

Parameters are fixed as Dirac observables

Abstract

Inspired by the recent proposal for the quantum effective dynamics of the Schwarzschild spacetime given in \cite{AOS1}, we investigate the effective dynamics of the loop quantized Janis-Newman-Winicour (JNW) spacetime which is an extension of the Schwarzschild spacetime with an extra minimally coupled massless scalar field. Two parameters are introduced in order to regularize the Hamiltonian constraint in the quantum effective dynamics. These two parameters are assumed to be Dirac observables when the effective dynamics is solved. By carefully choosing appropriate conditions for these two parameters, we completely determine them, and the resulted new effective description of the JNW spacetime leads to a well behaved quantum dynamics which on one hand resolves the classical singularities, and on the other hand, agrees with the classical dynamics in the low curvature region.