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Related papers: A Cosmological Sector in Loop Quantum Gravity

200 papers

The Gowdy cosmologies provide a suitable arena to further develop Loop Quantum Cosmology, allowing the presence of inhomogeneities. For the particular case of Gowdy spacetimes with the spatial topology of a three-torus and a content of…

General Relativity and Quantum Cosmology · Physics 2010-09-22 L. J. Garay , M. Martín-Benito , G. A. Mena Marugán

We study homogenous and isotropic quantum cosmology using the spinfoam formalism of Loop Quantum Gravity (LQG). We define a coupling of a scalar field to the 4-dimensional Lorentzian Engle-Pereira-Rovelli-Livine (EPRL) spinfoam model. We…

General Relativity and Quantum Cosmology · Physics 2024-02-14 Muxin Han , Hongguang Liu , Dongxue Qu , Francesca Vidotto , Cong Zhang

We study a class of theories in which space-time is treated classically, while interacting with quantum fields. These circumvent various no-go theorems and the pathologies of semi-classical gravity, by being linear in the density matrix and…

High Energy Physics - Theory · Physics 2022-02-15 Jonathan Oppenheim , Zachary Weller-Davies

Several approaches to the dynamics of loop quantum gravity involve discretizing the equations of motion. The resulting discrete theories are known to be problematic since the first class algebra of constraints of the continuum theory…

General Relativity and Quantum Cosmology · Physics 2009-01-16 Rodolfo Gambini , Jorge Pullin

Building upon our recently established correspondence between quantum cosmology and the hydrogen atom [1], we investigate the specific sector of a negative cosmological constant ($\Lambda < 0$) in a flat FLRW universe with dust. While the…

General Relativity and Quantum Cosmology · Physics 2026-01-29 Dipayan Mukherjee , Harkirat Singh Sahota , S. Shankaranarayanan

In this work we propose a new general model of eternal cyclic Universe. We start from the assumption that quantum gravity corrections can be effectively accounted by the addition of higher order curvature terms in the Lagrangian density for…

General Relativity and Quantum Cosmology · Physics 2017-06-06 Petar Pavlovic , Marko Sossich

Based on the foundational aspects which have been discussed as consequences of ongoing research on loop quantum gravity in the first part of this paper, the holistic aspects of the latter are discussed in this second part, aiming at a…

General Physics · Physics 2007-05-23 Rainer E. Zimmermann

We present a straightforward and self-contained introduction to the basics of the loop approach to quantum gravity, and a derivation of what is arguably its key result, namely the spectral analysis of the area operator. We also discuss the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Carlo Rovelli , Peush Upadhya

A brief review of various numerical techniques used in loop quantum cosmology and results is presented. These include the way extensive numerical simulations shed insights on the resolution of classical singularities, resulting in the key…

General Relativity and Quantum Cosmology · Physics 2013-07-11 Parampreet Singh

Classical cosmology exhibits a particular kind of scaling symmetry. The dynamics of the invariants of this symmetry forms a system that exhibits many of the features of open systems such as the non-conservation of mechanical energy and the…

General Relativity and Quantum Cosmology · Physics 2024-03-13 Sean Gryb , David Sloan

A model is proposed to demonstrate that classical general relativity can emerge from loop quantum gravity, in a relational description of gravitational field in terms of coordinates given by matter. Local Dirac observables and coherent…

General Relativity and Quantum Cosmology · Physics 2011-03-29 Chun-Yen Lin

In a recent proposal using the group field theory approach, a spatially homogeneous (generally anisotropic) universe is described as a quantum gravity condensate of "atoms of space," which allows the derivation of an effective cosmological…

General Relativity and Quantum Cosmology · Physics 2015-02-23 Steffen Gielen

Coupling any interacting quantum mechanical system to gravity in one dimension requires the cosmological constant to belong to the matter energy spectrum and thus to be quantized, even though the gravity sector is free of any quantum…

High Energy Physics - Theory · Physics 2007-05-23 Jan Govaerts

This paper provides a prospectus for a new way of thinking about the wavefunction of the universe: a $\Psi$-epistemic quantum cosmology. We present a proposal that, if successfully implemented, would resolve the cosmological measurement…

General Relativity and Quantum Cosmology · Physics 2017-11-15 Peter W. Evans , Sean Gryb , Karim P. Y. Thébault

This article presents the lattice-smeared gravity phase space reduction defined by the cosmological gauge-fixing conditions. These conditions are specified to reduce the SU(2) symmetry and the spatial diffeomorphism invariance of the loop…

General Relativity and Quantum Cosmology · Physics 2021-05-28 Jakub Bilski

The path-integral formulation of quantum cosmology with a massless scalar field as a sum-over-histories of volume transitions is discussed, with particular but non-exclusive reference to loop quantum cosmology. Exploiting the analogy with…

General Relativity and Quantum Cosmology · Physics 2011-07-08 Gianluca Calcagni , Steffen Gielen , Daniele Oriti

We show that the quantization ambiguities of loop quantum cosmology, when considered in wider generality, can be used to produce discretionary dynamical behavior. There is an infinite dimensional space of ambiguities which parallels the…

General Relativity and Quantum Cosmology · Physics 2023-05-03 Lautaro Amadei , Alejandro Perez , Salvatore Ribisi

An one-parameter regularization freedom of the Hamiltonian constraint for loop quantum gravity is analyzed. The corresponding spatially flat, homogenous and isotropic model includes the two well-known models of loop quantum cosmology as…

General Relativity and Quantum Cosmology · Physics 2021-11-12 Xiangdong Zhang , Gaoping Long , Yongge Ma

The use of non-regular representations of the Heisenberg-Weyl commutation relations has proved to be useful for studying conceptual and technical issues in quantum gravity. Of particular relevance is the study of Loop Quantum Cosmology…

General Relativity and Quantum Cosmology · Physics 2011-04-11 Alejandro Corichi , Tatjana Vukasinac , Jose A. Zapata

A new approach to a unified theory of quantum gravity based on noncommutative geometry and canonical quantum gravity is presented. The approach is built around a *-algebra generated by local holonomy-diffeomorphisms on a 3-manifold and a…

Mathematical Physics · Physics 2015-06-11 Johannes Aastrup , Jesper M. Grimstrup