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We study quantum cosmology with conformal matter comprising a perfect radiation fluid and a number of conformally coupled scalar fields. Focusing initially on the collective coordinates (minisuperspace) associated with homogeneous,…

High Energy Physics - Theory · Physics 2016-07-07 Steffen Gielen , Neil Turok

In this paper we study the quantum cosmology of homogeneous and isotropic cosmology, via the Weyl-Wigner-Groenewold-Moyal formalism of phase space quantization, with perfect fluid as a matter source. The corresponding quantum cosmology is…

General Relativity and Quantum Cosmology · Physics 2017-01-25 M. Rashki , S. Jalalzadeh

We construct a Bohmian quantum cosmological model for a spatially flat Friedmann Robertson Walker universe filled with a single scalar field whose potential provides a unified description of cold dark matter and dark energy at the…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Spyros Basilakos , Gerasimos Kouniatalis , Emmanuel N. Saridakis , Charalampos Tzerefos

Quantum cosmology in general denotes the application of quantum physics to the whole universe and thus gives rise to many realizations and examples, covering problems at different mathematical and conceptual levels. It is related to quantum…

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

In the present paper, we canonically quantize an homogeneous and isotropic Ho\v{r}ava-Lifshitz cosmological model, with constant positive spatial sections and coupled to radiation. We consider the projectable version of that gravitational…

General Relativity and Quantum Cosmology · Physics 2019-08-07 G. Oliveira-Neto , L. G. Martins , G. A. Monerat , E. V. Corrêa Silva

In the recent article Phys. Rev. D 100, no. 4, 043533 (2019) a compact phase space generalization of the flat de Sitter cosmology has been proposed. The main advantages of the compactification is that physical quantities are bounded, and…

General Relativity and Quantum Cosmology · Physics 2021-06-09 Danilo Artigas , Sean Crowe , Jakub Mielczarek

In the last 20 years, loop quantum gravity, a background independent approach to unify general relativity and quantum mechanics, has been widely investigated. The aim of loop quantum gravity is to construct a mathematically rigorous,…

General Relativity and Quantum Cosmology · Physics 2007-06-25 Muxin Han

We apply the de Broglie-Bohm interpretation to the Wheeler-DeWitt equation for the quantum FRW cosmological model with a minimal massless scalar field. We find that the quantum FRW cosmological model has quantum potential dominated…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Sang Pyo Kim

We propose a Hamiltonian formalism for a generalized Friedmann-Roberson-Walker cosmology model in the presence of both a variable equation of state (EOS) parameter $w(a)$ and a variable cosmological constant $\Lambda(a)$, where $a$ is the…

High Energy Physics - Theory · Physics 2008-11-26 Jie Ren , Xin-He Meng , Liu Zhao

We formulate a ''minimal'' interpretational scheme for fairly general (minisuperspace) quantum cosmological models. Admitting as few exact mathematical structure as is reasonably possible at the fundamental level, we apply approximate…

General Relativity and Quantum Cosmology · Physics 2008-02-03 Franz Embacher

We give an explicit, rigorous framework for calculating quantum probabilities in a model theory of quantum gravity. Specifically, we construct the decoherence functional for the Wheeler-DeWitt quantization of a flat…

General Relativity and Quantum Cosmology · Physics 2011-01-20 David A. Craig , Parampreet Singh

Using a particular Hilbert space representation of minimum-length deformed quantum mechanics, we show that the resolution of the wave-function singularities for strongly attractive potentials, as well as cosmological singularity in the…

High Energy Physics - Theory · Physics 2014-02-19 Michael Maziashvili , Luka Megrelidze

We develop an action principle for those models arising from isotropic loop quantum cosmology, and show that there is a natural conserved quantity $Q$ for the discrete difference equation arising from the Hamiltonian constraint. This…

General Relativity and Quantum Cosmology · Physics 2013-04-04 Daniel Cartin

Inhomogeneities are introduced in loop quantum cosmology using regular lattice states, with a kinematical arena similar to that in homogeneous models considered earlier. The framework is intended to encapsulate crucial features of…

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

In loop quantum cosmology the quantum dynamics is well understood. We approximate the full quantum dynamics in the infinite dimensional Hilbert space by projecting it on a finite dimensional submanifold thereof, spanned by suitably chosen…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Victor Taveras

Proposing smooth initial conditions is one of the most important tasks in quantum cosmology. On the other hand, the low-energy effective action, appearing in the semiclassical path integral, can get nontrivial quantum corrections near…

General Relativity and Quantum Cosmology · Physics 2018-11-07 Suddhasattwa Brahma , Dong-han Yeom

The "improved dynamics" of loop quantum cosmology is extended to include anisotropies of the Bianchi I model. As in the isotropic case, a massless scalar field serves as a relational time parameter. However, the extension is non-trivial…

General Relativity and Quantum Cosmology · Physics 2010-04-14 Abhay Ashtekar , Edward Wilson-Ewing

The existence of a quantum bounce in isotropic spacetimes is a key result in loop quantum cosmology (LQC), which has been demonstrated to arise in all the models studied so far. In most of the models, the bounce has been studied using…

General Relativity and Quantum Cosmology · Physics 2017-06-20 Peter Diener , Brajesh Gupt , Parampreet Singh

The dynamics of a flat Friedmann-Lema\^{i}tre-Robertson-Walker model minimally coupled to a massless scalar field has been intensively studied in the context of Loop Quantum Cosmology. This model admits an appropriate solvable…

General Relativity and Quantum Cosmology · Physics 2019-02-27 Mercedes Martín-Benito , Rita B. Neves

Spatially homogeneous universes can be described in (loop) quantum gravity as condensates of elementary excitations of space. Their treatment is easiest in the second-quantised group field theory formalism which allows the adaptation of…

General Relativity and Quantum Cosmology · Physics 2014-07-24 Steffen Gielen