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Canonical quantization of an action containing curvature squared term requires introduction of an auxiliary variable. Boulware etal[1] prescribed a technique to choose such a variable, by taking derivative of an action with respect to the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 A. K. Sanyal , B. Modak

A bouncing scenario of a flat homogeneous and isotropic universe is explored by using the reconstruction technique for the power-law parametrization of the Hubble parameter in a modified gravity theory with higher-order curvature and trace…

General Relativity and Quantum Cosmology · Physics 2023-04-03 J. K. Singh , Harshna Balhara , Kazuharu Bamba , J. Jena

We quantize an inhomogeneous cosmological model using techniques that include polymeric quantization. More explicitly, we construct well defined operators to represent the constraints and find the physical Hilbert space formed by their…

General Relativity and Quantum Cosmology · Physics 2009-02-23 Mercedes Martin-Benito , Luis J. Garay , Guillermo A. Mena Marugan

In this paper we discuss models satisfying the limiting curvature condition. For this purpose we modify the Einstein-Hilbert action by adding a term which restricts the growth of curvature. We analyze cosmological solutions in such models.…

High Energy Physics - Theory · Physics 2021-11-30 Valeri P. Frolov , Andrei Zelnikov

In the last decade, progress on quantization of homogeneous cosmological spacetimes using techniques of loop quantum gravity has led to insights on various fundamental questions and has opened new avenues to explore Planck scale physics.…

General Relativity and Quantum Cosmology · Physics 2016-12-06 Ivan Agullo , Parampreet Singh

We describe quantization schemes for scalar field cosmology in the metric variables with fundamental discreteness imposed with a lattice. The variables chosen for quantization determine the lattice, and each lattice produces distinct…

General Relativity and Quantum Cosmology · Physics 2025-07-18 Mustafa Saeed , Viqar Husain

We present a systematic study of the cosmological dynamics resulting from an effective Hamiltonian, recently derived in loop quantum gravity using Thiemann's regularization and earlier obtained in loop quantum cosmology (LQC) by keeping the…

General Relativity and Quantum Cosmology · Physics 2018-04-25 Bao-Fei Li , Parampreet Singh , Anzhong Wang

We consider the purely gravitational fourth-order (in the spacetime curvature) quantum corrections to the Einstein-Hilbert gravity action, coming from superstrings in the leading order with respect to the Regge slope parameter, and study…

High Energy Physics - Theory · Physics 2008-11-26 M. Iihoshi , S. V. Ketov

Loop quantum cosmology is a symmetry reduced quantization of cosmological spacetimes based on loop quantum gravity. While it has been successful in resolution of various cosmological singularities and connecting Planck scale physics to…

General Relativity and Quantum Cosmology · Physics 2019-12-25 Klaus Liegener , Parampreet Singh

We apply a singularity resolution technique utilized in loop quantum gravity to the polymer representation of quantum mechanics on R with the singular -1/|x| potential. On an equispaced lattice, the resulting eigenvalue problem is identical…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Viqar Husain , Jorma Louko , Oliver Winkler

We construct the higher order terms of curvatures in Lagrangians of the scale factor for the Friedmann-Lemaitre-Robertson-Walker universe, which are linear in the second derivative of the scale factor with respect to cosmic time. It is…

General Relativity and Quantum Cosmology · Physics 2013-04-02 Nahomi Kan , Koichiro Kobayashi , Kiyoshi Shiraishi

The leading quantum correction to Einstein-Hilbert Hamiltonian coming from large volume vacuum isotropic loop quantum cosmology, is independent of quantization ambiguity parameters. It is shown here that this correction can be viewed as…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Golam Mortuza Hossain

The inverse scale factor, which in classical cosmological models diverges at the singularity, is quantized in isotropic models of loop quantum cosmology by using techniques which have been developed in quantum geometry for a quantization of…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Martin Bojowald

In Loop Quantum Gravity mathematically rigorous models of full quantum gravity were proposed. In this paper we study a cosmological sector of one of the models describing quantum gravity with positive cosmological constant coupled to…

General Relativity and Quantum Cosmology · Physics 2022-11-09 Marcin Kisielowski

Loop Quantum Gravity is a background independent, nonperturbative approach to the quantization of General Relativity. Its application to models of interest in cosmology and astrophysics, known as Loop Quantum Cosmology, has led to new and…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Guillermo A. Mena Marugan

The way physics of loop quantum gravity is affected by the underlying quantization ambiguities is an open question. We address this issue in the context of loop quantum cosmology using gauge-covariant fluxes. Consequences are explored for…

General Relativity and Quantum Cosmology · Physics 2019-12-25 Klaus Liegener , Parampreet Singh

We study the quantization of spherically symmetric vacuum spacetimes within loop quantum gravity. In particular, we give additional details about our previous work in which we showed that one could complete the quantization the model and…

General Relativity and Quantum Cosmology · Physics 2016-12-20 Rodolfo Gambini , Javier Olmedo , Jorge Pullin

Using the complex-valued self-dual connection variables, the loop quantum cosmology of a closed Friedmann universe coupled to a massless scalar field is studied. It is shown how the reality conditions can be imposed in the quantum theory by…

General Relativity and Quantum Cosmology · Physics 2016-04-07 Edward Wilson-Ewing

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

Within loop quantum gravity we construct a coarse-grained approximation for the Einstein-Maxwell theory that yields effective Maxwell equations in flat spacetime comprising Planck scale corrections. The corresponding Hamiltonian is defined…

High Energy Physics - Theory · Physics 2009-11-07 Jorge Alfaro , Hugo A. Morales-Técotl , Luis F. Urrutia