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We consider the quasi-commutative approximation to a noncommutative geometry defined as a generalization of the moving frame formalism. The relation which exists between noncommutativity and geometry is used to study the properties of the…

High Energy Physics - Theory · Physics 2008-12-19 Maja Buric , John Madore , George Zoupanos

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

One presents a phase-space noncommutative extension of Quantum Cosmology in the context of a Kantowski-Sachs (KS) minisuperspace model. We obtain the Wheeler-DeWitt (WDW) equation for the noncommutative system through the ADM formalism and…

High Energy Physics - Theory · Physics 2009-07-24 C. Bastos , O. Bertolami , N. Dias , J. Prata

Cosmology is in an era of rapid discovery especially in areas related to dark energy, dark matter and inflation. Quantum cosmology treats the cosmology quantum mechanically and is important when quantum effects need to be accounted for,…

We propose a novel extension to the recently developed non-commutative Riemannian foliated branch-cut quantum gravity (BCQG). Based on an extended Faddeev-Jackiw symplectic deformation of the conventional Poisson algebra, we investigate…

We present exact quantum solutions for a noncommutative, multidimensional cosmological model and show that stabilization of extra dimensions sets in with the introduction of noncommutativity between the scale factors. An interpretation is…

General Relativity and Quantum Cosmology · Physics 2008-11-26 N. Khosravi , S. Jalalzadeh , H. R. Sepangi

Considering an arbitrary dimensional FLRW universe in the framework of a generalized S\'{a}ez--Ballester (SB) theory, we establish a noncommutative (NC) cosmological model. We concentrate on the predictions of NC model and compare them with…

General Relativity and Quantum Cosmology · Physics 2024-08-19 S. M. M. Rasouli , João Marto

In this paper we investigate to which extent noncommutativity, a intrinsically quantum property, may influence the Friedmann-Robertson-Walker cosmological dynamics at late times/large scales. To our purpose it will be enough to explore the…

General Relativity and Quantum Cosmology · Physics 2011-08-10 Octavio Obregon , Israel Quiros

We present a noncommutative extension of Quantum Cosmology and study the Kantowski-Sachs (KS) cosmological model requiring that the two scale factors of the KS metric, the coordinates of the system, and their conjugate canonical momenta do…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Catarina Bastos , Orfeu Bertolami , Nuno Costa Dias , João Nuno Prata

The WKB approximation for deformed space with minimal length is considered. The Bohr-Sommerfeld quantization rule is obtained. A new interesting feature in presence of deformation is that the WKB approximation is valid for intermediate…

Quantum Physics · Physics 2009-11-11 T. V. Fityo , I. O. Vakarchuk , V. M. Tkachuk

A new method for predicting inflationary cosmological perturbations, based on the Wentzel-Kramers-Brillouin (WKB) approximation, is presented. A general expression for the WKB scalar and tensor power spectra is derived. The main advantage…

Astrophysics · Physics 2009-11-07 Jerome Martin , Dominik J. Schwarz

In this work we extend and apply a previous proposal to study noncommutative cosmology to the FRW cosmological background coupled to a scalar field, this is done in classical and quantum scenarios. In both cases noncommutativity is…

General Relativity and Quantum Cosmology · Physics 2008-11-26 W. Guzmán , M. Sabido , J. Socorro

The problem of time emerging in the canonical quantization procedure of gravity signals a necessity to properly define a relational time parameter. Previous approaches, which are here briefly discussed, make use of the dependence of the…

General Relativity and Quantum Cosmology · Physics 2023-02-01 Giulia Maniccia , Giovanni Montani

We present a phase-space noncommutative version of quantum mechanics and apply this extension to Quantum Cosmology. We motivate this type of noncommutative algebra through the gravitational quantum well (GQW) where the noncommutativity…

High Energy Physics - Theory · Physics 2015-05-13 Catarina Bastos , Orfeu Bertolami , Nuno Dias , Joao Nuno Prata

Divergence in perturbative expansions is where interesting physics takes place. Particle production on time-dependent backgrounds, as one such example, is interpreted as transition from one vacuum to another. Vacuum is typically defined as…

High Energy Physics - Theory · Physics 2025-09-24 Ryo Namba , Motoo Suzuki

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 calculate the quantum gravitational corrections to the Mukhanov-Sasaki equation obtained by the canonical quantization of the inflaton-gravity system. Our approach, which is based on the Born-Oppenheimer decomposition of the resulting…

General Relativity and Quantum Cosmology · Physics 2020-02-05 A. Y. Kamenshchik , A. Tronconi , G. Venturi

It is well-known that the standard WKB approximation fails to provide semiclassical solutions in the vicinity of turning points. However, turning points arise in many cosmological scenarios. In a previous work, we obtained a new class of…

General Relativity and Quantum Cosmology · Physics 2016-02-12 Antonin Coutant

The problem of time is one of the most relevant open issues in canonical quantum gravity. Although there is a huge literature about this topic, a commonly accepted solution has not been found yet. Here, we focus on the semiclassical…

General Relativity and Quantum Cosmology · Physics 2021-05-18 Federico Di Gioia , Giulia Maniccia , Giovanni Montani , Jacopo Niedda

We propose a model for noncommutative quantum cosmology by means of a deformation of minisuperspace. For the Kantowski-Sachs metric we are able to find the exact wave function. We construct wave packets and show that new quantum states that…

High Energy Physics - Theory · Physics 2009-11-07 H. Garcia-Compean , O. Obregon , C. Ramirez
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