A short review of loop quantum gravity

A Ashtekar, E Bianchi - Reports on Progress in Physics, 2021 - iopscience.iop.org
An outstanding open issue in our quest for physics beyond Einstein is the unification of
general relativity (GR) and quantum physics. Loop quantum gravity (LQG) is a leading …

Coarse graining spin foam quantum gravity—a review

S Steinhaus - Frontiers in Physics, 2020 - frontiersin.org
In quantum gravity, we envision renormalization as the key tool for bridging the gap between
microscopic models and observable scales. For spin foam quantum gravity, which is defined …

Primordial black holes in loop quantum cosmology: the effect on the threshold

T Papanikolaou - Classical and Quantum Gravity, 2023 - iopscience.iop.org
Primordial black holes in loop quantum cosmology: the effect on the threshold - IOPscience
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Effective spin foam models for Lorentzian quantum gravity

SK Asante, B Dittrich… - Classical and Quantum …, 2021 - iopscience.iop.org
Making the Lorentzian path integral for quantum gravity well-defined and computable has
been a long standing challenge. In this work we adopt the recently proposed effective spin …

Mean-field phase transitions in tensorial group field theory quantum gravity

L Marchetti, D Oriti, AGA Pithis, J Thürigen - Physical Review Letters, 2023 - APS
Controlling the continuum limit and extracting effective gravitational physics are shared
challenges for quantum gravity approaches based on quantum discrete structures. The …

Complex critical points and curved geometries in four-dimensional Lorentzian spinfoam quantum gravity

M Han, Z Huang, H Liu, D Qu - Physical Review D, 2022 - APS
This paper focuses on the semiclassical behavior of the spinfoam quantum gravity in four
dimensions. There has been long-standing confusion, known as the flatness problem, about …

Complex actions and causality violations: Applications to Lorentzian quantum cosmology

SK Asante, B Dittrich… - Classical and Quantum …, 2023 - iopscience.iop.org
For the construction of the Lorentzian path integral for gravity one faces two main questions:
firstly, what configurations to include, in particular whether to allow Lorentzian metrics that …

Complex critical points in Lorentzian spinfoam quantum gravity: Four-simplex amplitude and effective dynamics on a double- complex

M Han, H Liu, D Qu - Physical Review D, 2023 - APS
The complex critical points are analyzed in the four-dimensional Lorentzian Engle-Pereira-
Rovelli-Livine spinfoam model in the large-j regime. For the four-simplex amplitude, taking …

Spinfoams and high-performance computing

P Dona, M Han, H Liu - Handbook of Quantum Gravity, 2023 - Springer
Numerical methods are a powerful tool for doing calculations in spinfoam theory. We review
the major frameworks available, their definition, and various applications. We start from …

Complete Barrett-Crane model and its causal structure

AF Jercher, D Oriti, AGA Pithis - Physical Review D, 2022 - APS
The causal structure is a quintessential element of continuum spacetime physics and needs
to be properly encoded in a theory of Lorentzian quantum gravity. Established spin foam …