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In this paper it is studied the cosmology of a homogeneous and isotropic spacetime endorsed with a conformally coupled massless scalar field. We find six different solutions of the Friedmann equation that represent six different types of…

General Relativity and Quantum Cosmology · Physics 2017-09-20 Salvador J. Robles-Perez

We investigate quantum effects in the evolution of general systems. For studying such temporal quantum phenomena, it is paramount to have a rigorous concept and profound understanding of the classical dynamics in such a system in the first…

Quantum Physics · Physics 2020-06-02 J. Sperling , I. A. Walmsley

The Lorentzian Hamiltonian constraint is solved for isotropic loop quantum cosmology coupled to a massless scalar field. As in the Euclidean case, the discreteness of quantum geometry removes the classical singularity from the quantum…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Franz Hinterleitner , Seth Major

The quantum cosmological version of a nonsingular Universe presented by Mukhanov and Brandenberger in the early nineties has been developed and the Hamilton Jacobi equation has been found under semiclassical (WKB) approximation. It has been…

General Relativity and Quantum Cosmology · Physics 2010-01-11 Abhik Kumar Sanyal

We show that the stationary quantum Hamilton-Jacobi equation of non-relativistic 1D systems, underlying Bohmian mechanics, takes the classical form with $\partial_q$ replaced by $\partial_{\hat q}$ where $d\hat q={dq\over…

High Energy Physics - Theory · Physics 2008-11-26 Alon E. Faraggi , Marco Matone

For many years, the most active area of quantum cosmology has been the issue of choosing boundary conditions for the wave function of a universe. Recently, loop quantum cosmology, which is obtained from loop quantum gravity, has shed new…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Martin Bojowald , Kevin Vandersloot

One of the interesting open problems in the cosmological framework is applying quantum physics to the whole universe, consistently. Although different conceptual aspects of quantum cosmology are still very much alive, till now, all the…

General Relativity and Quantum Cosmology · Physics 2022-06-22 S. H. Hendi , N. Riazi , S. N. Sajadi

The problem of the physical nature and the cosmological constant genesis is discussed. This problem can't be solved in terms of the current quantum field theory which operates with Higgs and nonperturbative vacuum condensates and takes into…

Astrophysics · Physics 2007-05-23 Vladimir Burdyuzha , Olga Lalakulich , Yuri Ponomarev , Grigory Vereshkov

We investigate scalar particle creation in a set of bouncing models where the bounce occurs due to quantum cosmological effects described by the Wheeler-DeWitt equation. The scalar field can be either conformally or minimally coupled to…

General Relativity and Quantum Cosmology · Physics 2017-02-03 Diogo C. F. Celani , Nelson Pinto-Neto , Sandro D. P. Vitenti

A bouncing universe is a viable candidate to solve the initial singularity problem. Here we consider bouncing solutions in the context of $f(R,\mathcal{G})$ gravity by using an order reduction technique which allows one to find solutions…

General Relativity and Quantum Cosmology · Physics 2020-06-24 Bruno J. Barros , Elsa M. Teixeira , Daniele Vernieri

We study the Newtonian cosmology taking into account the leading classical and quantum corrections of order $\mathcal{O}(G^{2})$ in the Newtonian potential. We first derive the modified Friedmann equations starting from the non-relativistic…

General Relativity and Quantum Cosmology · Physics 2023-03-22 Rituparna Mandal , Sunandan Gangopadhyay , Amitabha Lahiri

The bouncing evolution of an universe in Loop Quantum Cosmolgy can be described very well by a set of effective equations, involving a function $sin \; x$. Recently, we have generalised these effective equations to $(d + 1)$ dimensions and…

General Relativity and Quantum Cosmology · Physics 2017-08-02 S. Kalyana Rama

The old cosmological-constant (CC) problem indicates an inconsistency of the usual formulation of semiclassical gravity. The usual formulation of semiclassical gravity also seems to be inconsistent with the conventional interpretation of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 H. Nikolic

Using the idea of regularisation of singularities due to the variability of the fundamental constants in cosmology we study the cyclic universe models. We find two models of oscillating and non-singular mass density and pressure…

General Relativity and Quantum Cosmology · Physics 2016-07-27 Konrad Marosek , Mariusz P. Dabrowski , Adam Balcerzak

When the scale factor of expansion of the universe is written as $ a(t)\equiv Ae^{\alpha(t)}$, with $A$ as some real constant and $\alpha(t)$ a real function, the gravitational action $I_G$ appears in the same form as the matter action…

General Relativity and Quantum Cosmology · Physics 2023-01-30 Moncy Vilavinal John

Darwinian evolution requires (i) heritable records, (ii) repeatable copying with variation, and (iii) routine irreversibility. Categorical quantum mechanics (CQM) makes precise why ``copy'' and ``delete'' are not generic quantum operations:…

Quantum Physics · Physics 2026-02-19 Partha Ghose

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 study the role of non-perturbative quantum gravity effects in the Ekpyrotic/Cyclic model using the effective framework of loop quantum cosmology in the presence of anisotropies. We show that quantum geometric modifications to the…

General Relativity and Quantum Cosmology · Physics 2010-04-30 Thomas Cailleteau , Parampreet Singh , Kevin Vandersloot

The ADM approach to canonical general relativity combined with Dirac's method of quantizing constrained systems leads to the Wheeler-DeWitt equation. A number of mathematical as well as physical difficulties that arise in connection with…

General Relativity and Quantum Cosmology · Physics 2009-10-28 N. P. Landsman

The measurement problem is the issue of explaining how the objective classical world emerges from a quantum one. Here we take a different approach. We assume that there is an objective classical system, and then ask that the standard rules…

Quantum Physics · Physics 2025-10-13 Isaac Layton , Jonathan Oppenheim , Zachary Weller-Davies