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In this paper, we have presented a bouncing cosmological model of the Universe in an extended theory of gravity. The dynamical behaviour of the model obtained from the flat FLRW space-time along with the violation of null energy condition…

General Relativity and Quantum Cosmology · Physics 2022-04-22 A. S. Agrawal , Francisco Tello-Ortiz , B. Mishra , S. K. Tripathy

In loop quantum cosmology, the values of volume fluctuations and correlations determine whether the dynamics of an evolving state exhibits a bounce. Of particular interest are states that are supported only on either the positive or the…

General Relativity and Quantum Cosmology · Physics 2020-01-06 Martin Bojowald

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

General relativity predicts a singularity in the beginning of the universe being called big bang. Recent developments in loop quantum cosmology avoid the singularity and the big bang is replaced by a big bounce. A classical theory of…

General Physics · Physics 2011-02-08 Walter Petry

We study the third quantization of the Friedmann-Robertson-Walker cosmology with $N$-minimal massless fields. The third quantized Hamiltonian for the WDW equation in the minisuperspace consists of infinite number of intrinsic…

General Relativity and Quantum Cosmology · Physics 2012-12-24 Sang Pyo Kim

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

For the Bianchi type I space-time (vacuum or with a massless scalar field), the loop quantum cosmology bounce can be viewed as a rapid transition between two classical solutions, with a simple transformation rule relating the Kasner…

General Relativity and Quantum Cosmology · Physics 2018-03-14 Edward Wilson-Ewing

We show that the consistent application of the rules of quantum mechanics to cosmological systems inevitably results in the so-called multiverse states in which neither the background spacetime nor the inhomogeneous perturbation are in…

General Relativity and Quantum Cosmology · Physics 2025-03-20 Hervé Bergeron , Przemysław Małkiewicz , Patrick Peter

Quantum cosmology is crucial to understand the evolution of the early universe. Despite significant progress, challenges still remain. For example, the role of time in quantum cosmology is unclear. Furthermore, the influence of the…

General Relativity and Quantum Cosmology · Physics 2023-01-18 Hong Wang , Jin Wang

We discuss the way non-perturbative quantization of cosmological spacetimes in loop quantum cosmology provides insights on the physics of Planck scale and the resolution of big bang singularity. In recent years, rigorous examination of…

General Relativity and Quantum Cosmology · Physics 2009-03-27 Parampreet Singh

We study the dynamics of gauge-invariant scalar perturbations in cosmological scenarios with a modified Friedmann equation, such as quantum gravity bouncing cosmologies. We work within a separate universe approximation which captures…

General Relativity and Quantum Cosmology · Physics 2023-03-02 Steffen Gielen , Lisa Mickel

In this paper we investigate dynamics of the modified loop quantum cosmology models using dynamical systems methods. Modifications considered come from the choice of the different field strength operator $\hat{F}$ and result in different…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Orest Hrycyna , Jakub Mielczarek , Marek Szydlowski

We analyze the quantum dynamics of the Friedmann-Robertson-Walker Universe in the context of a Generalized Uncertainty Principle. Since the isotropic Universe dynamics resembles that of a one-dimensional particle, we quantize it with the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Marco Valerio Battisti , Giovanni Montani

We investigate an asymptotically spatially flat Robertson-Walker spacetime from two different perspectives. First, using von Neumann entropy, we evaluate the entanglement generation due to the encoded information in spacetime. Then, we work…

Quantum Physics · Physics 2017-06-21 Mehrnoosh Farahmand , Hosein Mohammadzadeh , Hossein Mehri-Dehnavi

We present a new variational method for investigating the ground state and out of equilibrium dynamics of quantum many-body bosonic and fermionic systems. Our approach is based on constructing variational wavefunctions which extend Gaussian…

Quantum Physics · Physics 2018-03-14 Tao Shi , Eugene Demler , J. Ignacio Cirac

We present a wide class of models which realise a bounce in a spatially flat Friedmann universe in standard General Relativity. The key ingredient of the theories we consider is a noncanonical, minimally coupled scalar field belonging to…

High Energy Physics - Theory · Physics 2011-11-14 Damien A. Easson , Ignacy Sawicki , Alexander Vikman

We discuss how the modifications of the standard Einstein's equations needed to support the cosmological bounce can at the same time lead to vanishing of the well known cosmological constant problem, while also studying the effects of…

General Relativity and Quantum Cosmology · Physics 2025-01-24 Petar Pavlović , Marko Sossich

We address the issue of quantifying the non-Gaussian character of a bosonic quantum state and introduce a non-Gaussianity measure based on the Hilbert-Schmidt distance between the state under examination and a reference Gaussian state. We…

Quantum Physics · Physics 2009-11-13 Marco G. Genoni , Matteo G. A. Paris , Konrad Banaszek

We analyze the problem of one dimensional quantum particle falling in a constant gravitational field, also known as the {\it bouncing ball}, employing a semiclassical approach known as momentous effective quantum mechanics. In this…

Quantum Physics · Physics 2019-04-16 Guillermo Chacon-Acosta , Hector Hernandez-Hernandez , Mercedes Velazquez

A research program within the scope of theories on "Emergent Quantum Mechanics" is presented, which has gained some momentum in recent years. Via the modeling of a quantum system as a non-equilibrium steady-state maintained by a permanent…

Quantum Physics · Physics 2015-01-14 Gerhard Groessing