English
Related papers

Related papers: A quantum cosmology and discontinuous signature ch…

200 papers

We study the relational cosmological dynamics emerging from interacting group field theory (GFT) models minimally coupled to a massless clock scalar field and a self-interacting scalar field. We focus on two broad classes of GFT…

General Relativity and Quantum Cosmology · Physics 2025-08-25 Tom R. Ladstätter , Luca Marchetti

We study the implications of a noncommutative geometry of the minisuperspace variables for the FRW universe with a conformally coupled scalar field. The investigation is carried out by means of a comparative study of the universe evolution…

High Energy Physics - Theory · Physics 2009-11-10 G. D. Barbosa

In an open Friedmann-Robertson-Walker (FRW) space background, we study the classical and quantum cosmological models in the framework of the recently proposed nonlinear massive gravity theory. Although the constraints which are present in…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Babak Vakili , Nima Khosravi

Loop quantum cosmology is an application of recent developments for a non-perturbative and background independent quantization of gravity to a cosmological setting. Characteristic properties of the quantization such as discreteness of…

Astrophysics · Physics 2009-11-13 Martin Bojowald

We study the classical and quantum models of a Friedmann-Robertson-Walker (FRW) cosmology, coupled to a perfect fluid, in the context of the scalar-metric gravity. Using the Schutz' representation for the perfect fluid, we show that, under…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Babak Vakili

The spin-statistics connection, quantum gravity and other physical considerations suggest that classical space-time topology is not an immutable attribute and can change in quantum physics. The implementation of topology change using…

High Energy Physics - Theory · Physics 2012-11-30 M. Asorey , A. P. Balachandran , G. Marmo , I. P. Costa e Silva , A. R. de Queiroz , P. Teotonio-Sobrinho , S. Vaidya

In this work we shall explore the effects of non commutativity in fractional classical and quantum schemes using the flat Friedmmann-Robertson-Walker (FRW) cosmological model coupled to a scalar field in the K-essence formalism. In previous…

General Relativity and Quantum Cosmology · Physics 2024-03-04 J. Socorro , J. Juan Rosales , Leonel Toledo-Sesma

In this article we investigate and develop specific aspects of Friedmann-Robertson-Walker (FRW) scalar field cosmologies related to the interpretation that canonical and phantom scalar field sources may be interpreted as cosmological…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Mauricio Cataldo , Fabiola Arevalo , Patricio Mella

We reconcile seemingly conflicting statements in the literature about the behavior of cosmological solutions in modified theories of gravity where the Einstein-Hilbert Lagrangian for gravity is modified by the addition of a function of the…

Astrophysics · Physics 2008-11-26 Ignacy Sawicki , Wayne Hu

In this paper we study the flat (k=0) cosmological FRW model with holonomy corrections of Loop Quantum Gravity. The considered universe contains a massless scalar field and the cosmological constant Lambda. We find analytical solutions for…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jakub Mielczarek , Tomasz Stachowiak , Marek Szydlowski

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 consider a higher dimensional gravity theory with a negative kinetic energy scalar field and a cosmological constant. We find that the theory admits an exact cosmological solution for the scale factor of our universe. It has the feature…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S. T. Hong , J. Lee , T. H. Lee , P. OH

A cosmological model describing the evolution of n Ricci-flat spaces (n>1) in the presence of 1-component perfect-fluid and minimally coupled scalar field is considered. When the pressures in all spaces are proportional to the density, the…

High Energy Physics - Theory · Physics 2009-09-25 V. D. Ivashchuk , V. N. Melnikov

We consider a little known aspect of signature change, where the overall sign of the metric is allowed to change, with physical implications. We show how, in different formulations of general relativity, this type of classical signature…

High Energy Physics - Theory · Physics 2023-11-01 Bruno Alexandre , Steffen Gielen , João Magueijo

The properties of the quantum universe on extremely small spacetime scales are studied in the semi-classical approach to the well-defined quantum model. It is shown that near the initial cosmological singularity point quantum gravity…

General Relativity and Quantum Cosmology · Physics 2010-04-30 V. E. Kuzmichev , V. V. Kuzmichev

We study scalar fields subject to an equation of the Klein-Gordon type in nonstationary spacetimes, such as those found in cosmology, assuming that all the relevant spatial dependence is contained in the Laplacian. We show that the field…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Laura Castelló Gomar , Guillermo A. Mena Marugán

A novel approach to quantization is shown to allow for superpositions of the cosmological constant in isotropic and homogeneous mini-superspace models. Generic solutions featuring such superpositions display unitary evolution and resolution…

General Relativity and Quantum Cosmology · Physics 2018-08-15 Sean Gryb , Karim P. Y. Thébault

In this work we consider a flat cosmological model with a set of fluids in the framework of supersymmetric cosmology. The obtained supersymmetric algebra allowed us to take quantum solutions. It is shown that only in the case of a…

General Relativity and Quantum Cosmology · Physics 2010-12-23 J. J. Rosales , V. I. Tkach

Invited contribution to the Encyclopedia of Mathematical Physics (2nd edition), providing an overview over some main ideas and results in quantum cosmology. Key points: Canonical quantisation of homogeneous, isotropic cosmology; discussion…

General Relativity and Quantum Cosmology · Physics 2025-02-28 Steffen Gielen

The dynamical behaviors of FRW Universe containing a posivive/negative potential scalar field in loop quantum cosmology scenario are discussed. The method of the phase-plane analysis is used to investigate the stability of the Universe. It…

General Relativity and Quantum Cosmology · Physics 2014-02-03 Xiao Liu , Kui Xiao , Jian-Yang Zhu