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Related papers: Revisiting Unimodular Quantum Cosmology

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This work proposes more solutions for the Wheeler-DeWitt equation in a flat FLRW minisuperspace. We study quantum cosmology in the framework of the de Broglie-Bohm interpretation and investigate the quantum cosmological effects throughout…

General Relativity and Quantum Cosmology · Physics 2024-03-15 Chia-Min Lin

The one-loop effective action for non-minimal scalar modified gravity on de Sitter background with a constant scalar field is found. The corresponding induced cosmological constant is evaluated. It is shown that quantum effects in…

General Relativity and Quantum Cosmology · Physics 2011-04-07 G. Cognola , E. Elizalde , S. Nojiri , S. D. Odintsov

We consider a scalar field with a negative kinetic term minimally coupled to gravity. We obtain an exact non-static spherically symmetric solution which describes a wormhole in cosmological setting. The wormhole is shown to connect two…

General Relativity and Quantum Cosmology · Physics 2010-11-19 S. V. Sushkov , S. -W. Kim

We propose an improved variant of the third-quantization scheme, for the spatially homogeneous and isotropic cosmological models in Einstein gravity coupled with a neutral massless scalar field. Our strategy is to specify a semi-Riemannian…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Daisuke Ida , Miyuki Saito

The classical and quantum dynamics of the Friedmann-Robertson-Walker Universe with massless scalar and massive fermion matter field as a source is discussed in the framework of the Dirac generalized Hamiltonian formalism. The Hamiltonian…

General Relativity and Quantum Cosmology · Physics 2009-11-07 A. M. Khvedelidze , Yu. G. Palii

We employ the semiclassical approximation to the Wheeler-DeWitt equation in the spatially flat de Sitter Universe to investigate the dynamics of a minimally coupled scalar field near the Planck scale. We find that, contrary to naive…

General Relativity and Quantum Cosmology · Physics 2008-11-07 Corrado Appignani , Roberto Casadio

Quantum cosmology may permit to determine the initial conditions of the Universe. In particular, it may select a specific model between many possible classical models. In this work, we study a quantum cosmological model based on the string…

General Relativity and Quantum Cosmology · Physics 2009-11-10 F. G. Alvarenga , A. B. Batista , J. C. Fabris

Using the Einstein-Hilbert approximation of asymptotically safe quantum gravity we present a consistent renormalization group based framework for the inclusion of quantum gravitational effects into the cosmological field equations. Relating…

High Energy Physics - Theory · Physics 2009-11-11 M. Reuter , F. Saueressig

Loop quantum cosmology was shown to interpolate between de Sitter and FLRW Universe phases through a bounce by including Euclidean and Lorentzian terms of the Hamiltonian constraint with weight one -that corresponding to classical General…

General Relativity and Quantum Cosmology · Physics 2025-04-01 Omar Gallegos , Tonatiuh Matos , Hugo A. Morales-Técotl

A discussion is given of the quantisation of a physical system with finite degrees of freedom subject to a Hamiltonian constraint by treating time as a constrained classical variable interacting with an unconstrained quantum state. This…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Charles Wang

We consider the quantum description of a toy model universe in which the Schwarzschild-de Sitter geometry emerges from the coherent state of a massless scalar field. Although highly idealised, this simple model allows us to find clear hints…

General Relativity and Quantum Cosmology · Physics 2022-01-19 Andrea Giusti , Silvia Buffa , Lavinia Heisenberg , Roberto Casadio

We study the cosmological evolution of a scalar field in Horndeski gravity, assuming that the scalar field is subdominant with respect to the cosmic fluid. We first analyse the most general shift-symmetric action that respects local Lorentz…

General Relativity and Quantum Cosmology · Physics 2020-04-08 Nicola Franchini , Thomas P. Sotiriou

Quantum Action Principle which has been used as a ground for a probabilistic interpretation of one-particle relativistic quantum mechanics \cite{GLL} is applied to quantum cosmology. The quantum creation of matter in a minisuperspace model…

General Relativity and Quantum Cosmology · Physics 2011-05-11 Natalia Gorobey , Alexander Lukyanenko

We present a detailed analysis of a quantum model for Loop Quantum Cosmology based on strict application of the Thiemann regularization algorithm for the Hamiltonian in Loop Quantum Gravity, extending the results presented previously in our…

General Relativity and Quantum Cosmology · Physics 2019-10-09 Mehdi Assanioussi , Andrea Dapor , Klaus Liegener , Tomasz Pawlowski

We investigate non-singular bounce and cyclic cosmological evolutions in a universe governed by the extended nonlinear massive gravity, in which the graviton mass is promoted to a scalar-field potential. The extra freedom of the theory can…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-05 Yi-Fu Cai , Caixia Gao , Emmanuel N. Saridakis

$f(Q)$ symmetric-teleparallel gravity is considered in view of Quantum Cosmology. Specifically, we derive cosmological equations for $f(Q)$ models and then investigate the related energy conditions. In the minisuperspace formalism, the…

General Relativity and Quantum Cosmology · Physics 2023-07-04 Francesco Bajardi , Salvatore Capozziello

We discuss the quantization of an unstable field through the construction of a "one-particle Hilbert space." The system considered here is a neutral scalar field evolving over a globally hyperbolic static spacetime and subject to a…

General Relativity and Quantum Cosmology · Physics 2017-01-12 William C. C. Lima

We consider multidimensional gravity with a Lagrangian containing the Ricci tensor squared and the Kretschmann invariant. In a Kaluza-Klein approach with a single compact extra space of arbitrary dimension, with the aid of a slow-change…

General Relativity and Quantum Cosmology · Physics 2009-11-13 K. A. Bronnikov , S. A. Kononogov , V. N. Melnikov , S. G. Rubin

We investigate aspects of quantum cosmology in relation to string cosmology systems that are described in terms of the Dirac-Born-Infeld action. Using the Silverstein-Tong model, we analyze the Wheeler-DeWitt equation for the rolling scalar…

High Energy Physics - Theory · Physics 2009-11-11 Anastasios Psinas

We prove that, at the mini superspace level, and for an arbitrary Brans-Dicke parameter, one cannot tell traditional Einstein-Hilbert gravity from local scale invariant Weyl-Dirac gravity. Both quantum mechanical cosmologies are governed by…

General Relativity and Quantum Cosmology · Physics 2019-09-20 Tomer Ygael , Aharon Davidson
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