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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

It has been known for some time that the cosmological Friedmann equation deduced from General Relativity can be also obtained within the Newtonian framework under certain assumptions. We use this result together with quantum corrections to…

General Relativity and Quantum Cosmology · Physics 2016-11-03 Pedro Bargueño , Sergio Bravo-Medina , Marek Nowakowski , Davide Batic

We give, in some detail, a critical overview over recent work towards deriving a cosmological phenomenology from the fundamental quantum dynamics of group field theory (GFT), based on the picture of a macroscopic universe as a "condensate"…

General Relativity and Quantum Cosmology · Physics 2016-08-19 Steffen Gielen , Lorenzo Sindoni

A bouncing scenario of a flat homogeneous and isotropic universe is explored by using the reconstruction technique for the power-law parametrization of the Hubble parameter in a modified gravity theory with higher-order curvature and trace…

General Relativity and Quantum Cosmology · Physics 2023-04-03 J. K. Singh , Harshna Balhara , Kazuharu Bamba , J. Jena

We deepen the analysis of the cosmological acceleration produced by quantum gravity dynamics in the formalism of group field theory condensate cosmology, treated at the coarse-grained level via a phenomenological model, in the language of…

General Relativity and Quantum Cosmology · Physics 2025-06-19 Daniele Oriti , Xiankai Pang

This contribution is an appetizer to the relatively young and fast evolving approach to quantum cosmology based on group field theory condensate states. We summarize the main assumptions and pillars of this approach which has revealed new…

General Relativity and Quantum Cosmology · Physics 2019-06-14 A. G. A. Pithis , M. Sakellariadou

We study cosmological solutions of Einstein gravity with a positive cosmological constant in diverse dimensions. These include big-bang models that re-collapse, big-bang models that approach de Sitter acceleration at late times, and bounce…

High Energy Physics - Theory · Physics 2009-11-07 K. R. Kristjansson , L. Thorlacius

Loop quantum cosmology homogeneous models with a massless scalar field show that the big-bang singularity can be replaced by a big quantum bounce. To gain further insight on the nature of this bounce, we study the semi-discrete loop quantum…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Pablo Laguna

Group field theory has shown to be a promising framework to derive cosmological predictions from full quantum gravity. In this brief note, we revisit the background dynamics when interaction terms are taken into account and conclude that,…

General Relativity and Quantum Cosmology · Physics 2023-09-06 Maxime De Sousa , Aurélien Barrau , Killian Martineau

In the framework of quasi-topological (QT) gravity, we propose a novel model which is characterized by a bounce of the spacetime such that the singularity in standard general relativity can be avoided in both cosmological and black hole…

General Relativity and Quantum Cosmology · Physics 2026-03-05 Yi Ling , Zhangping Yu

We use the separate universe framework to study cosmological perturbations within the group field theory formalism for quantum gravity, based on multi-condensate quantum states. Working with a group field theory action for gravity minimally…

General Relativity and Quantum Cosmology · Physics 2018-09-26 Florian Gerhardt , Daniele Oriti , Edward Wilson-Ewing

The investigation of quantum gravity effects in order to avoid the big bang singularity is a requisite, so that the idea of oscillating universes is introduced as an alternative for standard cosmological model. Therefore, the Friedmann…

General Relativity and Quantum Cosmology · Physics 2018-04-18 Amin. Salehi , Mojtaba. Mahmoudi fard

We examine the cosmological sector of a gauge theory of gravity based on the SO(4,2) conformal group of Minkowski space. We allow for conventional matter coupled to the spacetime metric as well as matter coupled to the field that gauges…

General Relativity and Quantum Cosmology · Physics 2017-05-02 Jack Gegenberg , Shohreh Rahmati , Sanjeev S. Seahra

Nonsingular bouncing cosmologies are realized in limiting curvature mimetic gravity by means of a multi-valued potential $f(\Box\phi)$ depending on the d'Alembertian of a scalar field $\phi$. We determine the functional form of such a…

General Relativity and Quantum Cosmology · Physics 2019-04-05 Marco de Cesare

Recent results have shown how quantum cosmology models can be derived from the effective dynamics of condensate states in group field theory (GFT), where 'cosmology is the hydrodynamics of quantum gravity': the classical Friedmann dynamics…

General Relativity and Quantum Cosmology · Physics 2016-10-27 Steffen Gielen

We analyse the emergent cosmological dynamics corresponding to the mean field hydrodynamics of quantum gravity condensates, in the tensorial group field theory formalism. We focus in particular on the cosmological effects of fundamental…

General Relativity and Quantum Cosmology · Physics 2022-01-05 Daniele Oriti , Xiankai Pang

We investigate the emergence of a quantum Big-Bounce in the context of an isotropic Universe, filled by a self-interacting scalar field, which plays the role of a physical clock. The bouncing cosmology is the result of a scattering process,…

General Relativity and Quantum Cosmology · Physics 2024-10-04 S. Lo Franco , G. Montani

In Loop Quantum Gravity mathematically rigorous models of full quantum gravity were proposed. In this paper we study a cosmological sector of one of the models describing quantum gravity with positive cosmological constant coupled to…

General Relativity and Quantum Cosmology · Physics 2022-11-09 Marcin Kisielowski

The dynamics of an inhomogeneous universe is studied with the methods of Loop Quantum Cosmology as an example of the quantization of vacuum cosmological spacetimes containing gravitational waves (Gowdy spacetimes). The analysis performed at…

General Relativity and Quantum Cosmology · Physics 2010-02-17 David Brizuela , Guillermo A. Mena Marugan , Tomasz Pawlowski

The Asymptotically Safe Gravity provides a framework for the description of gravity from the trans-Planckian regime to cosmological scales. According to this scenario, the cosmological constant and Newton's coupling are functions of the…

General Relativity and Quantum Cosmology · Physics 2018-03-14 Alfio Bonanno , Gabriele Gionti , Alessia Platania