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Related papers: Fermions in a loop quantum cosmological spacetime

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We discuss the freedom available in hybrid loop quantum cosmology to define canonical variables for the matter content and investigate whether this can be used to derive a quantum field theory with good properties for the matter sector. We…

General Relativity and Quantum Cosmology · Physics 2018-10-02 Beatriz Elizaga Navascués , Guillermo A. Mena Marugán , Santiago Prado Loy

This work pioneers the quantization of primordial fermion perturbations in hybrid Loop Quantum Cosmology (LQC). We consider a Dirac field coupled to a spatially flat, homogeneous, and isotropic cosmology, sourced by a scalar inflaton, and…

General Relativity and Quantum Cosmology · Physics 2017-09-08 Beatriz Elizaga Navascués , Mercedes Martín-Benito , Guillermo A. Mena Marugán

We use the freedom available in hybrid loop quantum cosmology to split the degrees of freedom between the geometry and the matter fields so as to build a quantum field theory for the matter content with good quantum properties. We…

General Relativity and Quantum Cosmology · Physics 2019-04-02 Beatriz Elizaga Navascués , Guillermo A. Mena Marugán , Santiago Prado

Certain time dependent configurations in the c=1 matrix model correspond to string theory backgrounds which have spacelike boundaries and appear geodesically incomplete. We investigate quantum mechanical properties of a class of such…

High Energy Physics - Theory · Physics 2008-11-07 Joanna L. Karczmarek

In this paper we investigate the scalar mode of first-order metric perturbations over spatially flat FRW spacetime when the holonomy correction is taken into account in the semi-classical framework of loop quantum cosmology. By means of the…

High Energy Physics - Theory · Physics 2010-05-28 Jian-Pin Wu , Yi Ling

Loop quantum cosmology has recently been applied in order to extend the analysis of primordial perturbations to the Planck era and discuss the possible effects of quantum geometry on the cosmic microwave background. Two approaches to loop…

General Relativity and Quantum Cosmology · Physics 2018-02-28 Beatriz Elizaga Navascués , Daniel Martín de Blas , Guillermo A. Mena Marugán

In the effective theory of loop quantum cosmology LQC, the influence of the holonomy correction (with $\overline{\mu}$-scheme) on the homogeneous and the inhomogeneous cosmological models have been extensively studied in the case of flat…

General Relativity and Quantum Cosmology · Physics 2023-10-12 Akram Hasseine

We consider the k=1 Friedman-Lemaitre-Robertson-Walker (FLRW) model within loop quantum cosmology (LQC), from the perspective of the two available quantization prescriptions. We focus our attention on the existence of the so called `inverse…

General Relativity and Quantum Cosmology · Physics 2016-04-28 Alejandro Corichi , Asieh Karami

In this paper we study dynamics of the closed FRW model with holonomy corrections coming from loop quantum cosmology. We consider models with a scalar field and cosmological constant. In case of the models with cosmological constant and…

General Relativity and Quantum Cosmology · Physics 2009-11-19 Jakub Mielczarek , Orest Hrycyna , Marek Szydlowski

We develop the formalism for the one-loop no-boundary state in a cosmological model with fermions. We use it to calculate the reduced density matrix for an inflaton field by tracing out the fermionic degrees of freedom, yielding both the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 A. Barvinsky , A. Kamenshchik , C. Kiefer

We present a systematic study of the cosmological dynamics resulting from an effective Hamiltonian, recently derived in loop quantum gravity using Thiemann's regularization and earlier obtained in loop quantum cosmology (LQC) by keeping the…

General Relativity and Quantum Cosmology · Physics 2018-04-25 Bao-Fei Li , Parampreet Singh , Anzhong Wang

With a well-motivated extension of higher order holonomy corrections, the quantum theory of loop quantum cosmology (LQC) for the $k=0$ Friedmann-Robertson-Walker model (with a free massless scalar) is rigorously formulated. The analytical…

General Relativity and Quantum Cosmology · Physics 2009-08-18 Dah-Wei Chiou , Li-Fang Li

In this paper, we show that the Hamiltonian approach to loop quantum gravity has a fermion doubling problem. To obtain this result, we couple loop quantum gravity to a free massless scalar and a chiral fermion field, gauge fixing the many…

General Relativity and Quantum Cosmology · Physics 2015-07-07 Jacob Barnett , Lee Smolin

We study the coupling of massive fermions to the quantum mechanical dynamics of spacetime emerging from the spinfoam approach in three dimensions. We first recall the classical theory before constructing a spinfoam model of quantum gravity…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Winston Fairbairn

In this work, we readdress the Dirac equation in the position-dependent mass (PDM) scenario. Here, one investigates the quantum dynamics of non-Hermitian fermionic particles with effective mass assuming a $(1+1)$-dimension flat spacetime.…

Quantum Physics · Physics 2023-03-22 F. C. E. Lima , L. N. Monteiro , C. A. S. Almeida

In the model of a fermion field coupled to loop quantum gravity, we consider the Gauss and the Hamiltonian constraints. According to the explicit solutions to the Gauss constraint, the fermion spins and the gravitational spin networks…

General Relativity and Quantum Cosmology · Physics 2022-06-14 Jerzy Lewandowski , Cong Zhang

In contrast to scalar and tensor modes, vector modes of linear perturbations around an expanding Friedmann--Robertson--Walker universe decay. This makes them largely irrelevant for late time cosmology, assuming that all modes started out at…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald , Golam Mortuza Hossain

We study the evolution of a homogeneous and isotropic spacetime whose spatial sections have three-torus topology, coupled to a massless scalar field with small scalar perturbations within loop quantum cosmology. We consider a proposal for…

General Relativity and Quantum Cosmology · Physics 2014-12-11 Mikel Fernández-Méndez , Guillermo A. Mena Marugán , Javier Olmedo

Quantum cosmological models are commonly described by means of semiclassical approximations in which a smooth evolution of the expectation values of elementary geometry operators replaces the classical and singular dynamics. The advantage…

General Relativity and Quantum Cosmology · Physics 2021-04-28 Przemysław Małkiewicz , Artur Miroszewski

We study the quantum cosmology of supersymmetric, homogeneous and isotropic, higher derivative models. We recall superfield actions obtained in previous works and give classically equivalent actions leading to second order equations for the…

General Relativity and Quantum Cosmology · Physics 2025-11-03 Nephtalí Eliceo Martínez-Pérez , Cupatitzio Ramírez
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