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The alternative dynamics of loop quantum cosmology is examined by the path integral formulation. We consider the spatially flat FRW models with a massless scalar field, where the alternative quantization inherit more features from full loop…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Li Qin , Guo Deng , Yongge Ma

We study the classical and quantum cosmology of a universe in which the matter content is a perfect fluid and the background geometry is described by a Bianchi type I metric. To write the Hamiltonian of the perfect fluid we use the Schutz…

General Relativity and Quantum Cosmology · Physics 2019-09-23 Fatimah Tavakoli , Babak Vakili

The Bianchi IX model has been used often to investigate the structure close to singularities of general relativity. Its classical chaos is expected to have, via the BKL scenario, implications even for the approach to general inhomogeneous…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Martin Bojowald , Ghanashyam Date , Golam Mortuza Hossain

General Relativity is an extremely successful theory, at least for weak gravitational fields, however, it breaks down at very high energies, such as in correspondence of the initial singularity. Quantum Gravity is expected to provide more…

General Relativity and Quantum Cosmology · Physics 2023-04-20 Ana Rita Ribeiro , Daniele Vernieri , Francisco S. N. Lobo

In this work we construct a noncommutative version of the Friedmann equations in the framework of effective loop quantum cosmology, extending and applying the ideas presented in a previous proposal by some of the authors. The model under…

General Relativity and Quantum Cosmology · Physics 2019-11-05 Luis Rey Díaz-Barrón , Abraham Espinoza-García , S. Pérez-Payán , J. Socorro

Quantum effects are expected to modify the cosmological dynamics of the early universe while maintaining some (potentially discrete) notion of space-time structure. In one approach, loop quantum cosmology, current models are shown here to…

General Relativity and Quantum Cosmology · Physics 2026-04-29 Martin Bojowald , Manuel Diaz , Erick I. Duque

It is shown that several prescriptions for the effective continuum limit of the flat Friedmann-Lemaitre-Robertson-Walker loop quantum cosmology can be understood as the exact classical limit of the Wheeler-DeWitt quantization of certain…

General Relativity and Quantum Cosmology · Physics 2025-04-23 Abraham Espinoza-García

Homogeneous cosmological models with non-vanishing intrinsic curvature require a special treatment when they are quantized with loop quantum cosmological methods. Guidance from the full theory which is lost in this context can be replaced…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald , Ghanashyam Date , Kevin Vandersloot

The approach of a quantum state to a cosmological singularity is studied through the evolution of its moments in a simple version of a Bianchi I model. In spite of the simplicity, the model exhibits several instructive and unexpected…

General Relativity and Quantum Cosmology · Physics 2020-06-03 Ana Alonso-Serrano , Martin Bojowald , David Brizuela

In the context of the Loop Quantum Cosmology we have analysed the holonomy correction to the classical evolution of the simplified Bianchi I model in the presence of vector fields. For the Universe dominated by a massive vector field or by…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Michal Artymowski , Zygmunt Lalak

The non-diagonal Bianchi models are studied in the loop framework for their classical and quantum formulation. The expressions of the Ashtekar-Barbero-Immirzi variables and their properties are found to provide a loop quantization of these…

General Relativity and Quantum Cosmology · Physics 2023-06-19 Matteo Bruno , Giovanni Montani

We construct physical semi-classical states annihilated by the Hamiltonian constraint operator in the framework of loop quantum cosmology as a method of systematically determining the regime and validity of the semi-classical limit of the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Parampreet Singh , Kevin Vandersloot

We complete the canonical quantization of the vacuum Bianchi I model within the improved dynamics scheme of loop quantum cosmology, characterizing the Hilbert structure of the physical states and providing a complete set of observables…

General Relativity and Quantum Cosmology · Physics 2015-05-30 M Martín-Benito , L J Garay , G A Mena Marugán , E. Wilson-Ewing

In this contribution we consider the issue of singularity resolution within loop quantum cosmology (LQC) for different homogeneous models. We present results of numerical evolutions of effective equations for both isotropic as well as…

General Relativity and Quantum Cosmology · Physics 2012-12-04 Alejandro Corichi , Asieh Karami , Edison Montoya

We study the anisotropic Bianchi type-I cosmological model at late times, taking into account quantum gravitational corrections in the formalism of the exact renormalization group flow of the effective average action for gravity. The…

General Relativity and Quantum Cosmology · Physics 2020-02-24 Rituparna Mandal , Sunandan Gangopadhyay , Amitabha Lahiri

A Bianchi type-I cosmological model in the presence of a magnetic flux along a cosmological string is considered. The first objective of this study is to investigate Einstein equations using a tractable assumption usually accepted in the…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Victor Rikhvitsky , Bijan Saha , Mihai Visinescu

Fractional cosmology modifies the standard derivative to Caputo's fractional derivative of order $\mu$, generating changes in General Relativity. Friedmann equations are modified, and the evolution of the species densities depends on $\mu$…

General Relativity and Quantum Cosmology · Physics 2022-10-26 Miguel A. García-Aspeitia , Guillermo Fernandez-Anaya , A. Hernández-Almada , Genly Leon , Juan Magaña

We analyze the quantum Bianchi I model in the setting of the nonstandard loop quantum cosmology. Elementary observables are used to quantize the volume operator. The spectrum of the volume operator is bounded from below and discrete. The…

General Relativity and Quantum Cosmology · Physics 2011-04-04 Przemyslaw Malkiewicz , Wlodzimierz Piechocki , Piotr Dzierzak

The primary aim of this work is to explore feasible bouncing cosmological solutions in the framework of $f(\mathcal{Q}, \mathcal{C})$ gravity, where $\mathcal{Q}$ denotes non-metricity and $\mathcal{C}$ indicates the boundary term. To…

General Relativity and Quantum Cosmology · Physics 2025-08-12 M. Sharif , M. Zeeshan Gul , Ahmad Nawaz

In this paper we introduce a numerical approximation technique to obtain pre-classical solutions to models of loop quantum gravity. In particular, we apply the technique to vacuum Bianchi I cosmological models and recover known solutions.…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Seth Connors , Gaurav Khanna