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Related papers: Cosmological dynamics in spin-foam loop quantum co…

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The stochastic properties of cosmological perturbations are best defined through the Fourier expansion in a finite box. I discuss the reasons for that with reference the curvature perturbation, and explore some issues arising from it.

Astrophysics · Physics 2008-11-26 David H. Lyth

This introductory review is addressed to beginning researchers. Some of the distinguishing features of loop quantum gravity are illustrated through loop quantum cosmology of FRW models. In particular, these examples illustrate: i) how…

General Relativity and Quantum Cosmology · Physics 2010-11-11 Abhay Ashtekar

Volume operators measuring the total volume of space in a loop quantum theory of cosmological models are constructed. In the case of models with rotational symmetry an investigation of the Higgs constraint imposed on the reduced connection…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Martin Bojowald

We explore the dynamical behaviour of cosmological models involving a scalar field (with an exponential potential and a canonical kinetic term) and a matter fluid with spatial curvature included in the equations of motion. Using…

General Relativity and Quantum Cosmology · Physics 2016-10-13 Mateja Gosenca , Peter Coles

We study the dynamics of a cosmological bubble wall beyond the approximation of an infinitely thin wall. In a previous paper, we discussed the range of validity of this approximation and estimated the first-order corrections due to the…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-03 Ariel Mégevand , Federico Agustín Membiela

The use of techniques from loop quantum gravity for cosmological models may solve some difficult problems in quantum cosmology. The solutions under a number of circumstances have been well studied. We will analyse the behaviour of solutions…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Daniel Green , William G. Unruh

We review the most recent progress in our understanding of quantum mechanical observables in cosmology in the perturbative regime. It relies on an approach that considers them directly as functions of the data at the space-like boundary at…

High Energy Physics - Theory · Physics 2022-12-07 Paolo Benincasa

Any approach to pure quantum gravity must eventually face the question of coupling quantum matter to the theory. In the past, several ways of coupling matter to spin foam quantum gravity have been proposed, but the dynamics of the coupled…

General Relativity and Quantum Cosmology · Physics 2022-11-30 Masooma Ali , Sebastian Steinhaus

Vertex amplitudes are elementary contributions to the transition amplitudes in the spin foam models of quantum gravity. The purpose of this article is make the first step towards computing vertex amplitudes with the use of quantum…

General Relativity and Quantum Cosmology · Physics 2019-06-20 Jakub Mielczarek

The expansion of our universe, when followed backward in time, implies that it emerged from a phase of huge density, the big bang. These stages are so extreme that classical general relativity combined with matter theories is not able to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Martin Bojowald

Spin-foam models are hoped to provide a dynamics for loop quantum gravity. These start from the Plebanski formulation of gravity, in which gravity is obtained from a topological field theory, BF theory, through constraints, which, however,…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Jonathan Engle

We note that in general there exist two basic aspects in any branch of physics, including cosmology - one dealing with the attributes of basic constituents and forces of nature, the other dealing with how structures arise from them and how…

General Relativity and Quantum Cosmology · Physics 2007-05-23 B. L. Hu

The cosmological implications of introducing a variation to the fine structure `constant', \alpha are examined within the context of Loop Quantum Cosmology. The evolution of \alpha is described using the model introduced by Bekenstein,…

General Relativity and Quantum Cosmology · Physics 2016-04-29 David Sloan

We develop a framework to simulate quantum field theories (QFTs) with boundaries in $(1+1)$-dimenmsional curved spacetimes by employing open spin systems. Building upon our previous work that established a mapping from spin systems to QFTs…

High Energy Physics - Theory · Physics 2026-02-23 Shunichiro Kinoshita , Keiju Murata , Daisuke Yamamoto , Ryosuke Yoshii

Large-scale simulations of the spin dynamics in quantum dots subjected to trains of periodic laser pulses enable us to describe and understand related experiments. By comparing the data for different models to experimental results, we gain…

Mesoscale and Nanoscale Physics · Physics 2022-01-10 Philipp Schering , Philipp W. Scherer , Götz S. Uhrig

A quantum communication protocol between harmonic oscillator detectors, interacting with a quantum field, is developed in a cosmological expanding background. The aim is to see if the quantum effects arising in an expanding universe, such…

General Relativity and Quantum Cosmology · Physics 2025-06-10 Alessio Lapponi , Orlando Luongo , Stefano Mancini

The main objective of this manuscript is to investigate the bouncing cosmology in the background of $f(\mathcal{Q})$ gravity, where $\mathcal{Q}$ defines the non-metricity. For this purpose, we use the reconstruction approach and consider a…

General Relativity and Quantum Cosmology · Physics 2024-04-02 M. Sharif , M. Zeeshan Gul , Nusrat Fatima

We study perturbation theory for spin foam models on triangulated manifolds. Starting with any model of this sort, we consider an arbitrary perturbation of the vertex amplitudes, and write the evolution operators of the perturbed model as…

General Relativity and Quantum Cosmology · Physics 2023-03-07 John C. Baez

Quantum cosmology offers a unique stage to address questions of time related to its underlying (and perhaps truly quantum dynamical) meaning as well as its origin. Some of these issues can be analyzed with a general scheme of quantum…

General Relativity and Quantum Cosmology · Physics 2012-07-25 Martin Bojowald

Using dynamical system analysis, we explore the cosmology of theories of order up to eight order of the form $f(R, \Box R)$. The phase space of these cosmology reveals that higher-order terms can have a dramatic influence on the evolution…

General Relativity and Quantum Cosmology · Physics 2019-05-08 Sante Carloni , João Luís Rosa , José P. S. Lemos
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