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Related papers: Loop quantum modified gravity and its cosmological…

200 papers

In this review we present a thoroughly comprehensive survey of recent work on modified theories of gravity and their cosmological consequences. Amongst other things, we cover General Relativity, Scalar-Tensor, Einstein-Aether, and Bimetric…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Timothy Clifton , Pedro G. Ferreira , Antonio Padilla , Constantinos Skordis

We give an overview of the two different methods that have been introduced in order to describe the dynamics of constrained quantum systems; the symplectic formulation and the metric formulation. The symplectic method extends the work of…

Quantum Physics · Physics 2015-05-13 Anna C. T. Gustavsson

Recent and upcoming experimental data as well as the possibility of rich phenomenology have spiked interest in studying the quantum effects in cosmology at low (inflation-era) energy scales. One of the approaches to find covariant quantum…

General Relativity and Quantum Cosmology · Physics 2020-07-28 Sandeep Aashish

The gravitational dynamics of 3+1 dimensional covariant quantum spacetime in the IKKT or IIB matrix model is studied at one loop, combining the Yang-Mills-type matrix action with the induced Einstein-Hilbert action. This combined action…

High Energy Physics - Theory · Physics 2026-01-14 Harold C. Steinacker

In this paper is considered a generalized quantization principle for the gravitational field in canonical quantum gravity, especially with respect to quantum geometrodynamics. This assumption can be interpreted as a transfer from the…

General Relativity and Quantum Cosmology · Physics 2012-08-07 Martin Kober

In this work we derive general quantum phenomenological equations of gravitational dynamics and analyse its features. The derivation uses the formalism developed in thermodynamics of spacetime and introduces low energy quantum gravity…

General Relativity and Quantum Cosmology · Physics 2021-02-03 Ana Alonso-Serrano , Marek Liška

We study the cosmology of a quadratic metric-compatible torsionful gravity theory in the presence of a perfect hyperfluid. The gravitational action is an extension of the Einstein-Cartan theory given by the usual Einstein-Hilbert…

General Relativity and Quantum Cosmology · Physics 2021-10-07 Damianos Iosifidis , Lucrezia Ravera

Quantum gravitational effects in loop quantum cosmology lead to a resolution of the initial singularity and have the potential to solve the horizon problem and generate a quasi scale-invariant spectrum of density fluctuations. We consider…

Astrophysics · Physics 2008-11-26 Joao Magueijo , Parampreet Singh

The spectrum of primordial perturbations obtained by calculating the quantum gravitational corrections to the dynamics of scalar perturbations is compared with Planck 2013 and BICEP2/{\it Keck Array} public data. The quantum gravitational…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Alexander Y. Kamenshchik , Alessandro Tronconi , Giovanni Venturi

The formation of cosmic structures is an important diagnostic for both the dynamics of the cosmological model and the underlying theory of gravity. At the linear level of these structures, certain degeneracies remain between different…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-02 Lavinia Heisenberg , Matthias Bartelmann

We study the growth of subhorizon perturbations in brane-induced gravity using perturbation theory. We solve for the linear evolution of perturbations taking advantage of the symmetry under gauge transformations along the extra-dimension to…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-10 Roman Scoccimarro

Emergent modified gravity has shown that the canonical formulation of general relativity gives rise to a larger class of covariant modifications than action-based approaches, so far in symmetry-reduced models. This outcome is made possible…

General Relativity and Quantum Cosmology · Physics 2026-04-29 Martin Bojowald , Manuel Diaz , Erick I. Duque

Being able to perform explicit computations in a nonperturbative, Planckian regime is key to understanding quantum gravity as a fundamental theory of gravity and spacetime. Rather than a variety of different approaches to quantum gravity,…

High Energy Physics - Theory · Physics 2025-01-31 R. Loll

Using general features of recent quantizations of the Hamiltonian constraint in loop quantum gravity and loop quantum cosmology, a dynamical interpretation of the constraint equation as evolution equation is presented. This involves a…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Martin Bojowald

We present a short review describing the use of noncommutative space-time in quantum-deformed dynamical theories: classical and quantum mechanics as well as classical and quantum field theory. We expose the role of Hopf algebras and their…

High Energy Physics - Theory · Physics 2011-01-10 Jerzy Lukierski

A quantum hamiltonian which evolves the gravitational field according to time as measured by constant surfaces of a scalar field is defined through a regularization procedure based on the loop representation, and is shown to be finite and…

General Relativity and Quantum Cosmology · Physics 2011-09-30 Carlo Rovelli , Lee Smolin

We propose the implementation of Galileo group symmetry operations or, in general, linear coordinate transformations, in a quantum simulator. With an appropriate encoding, unitary gates applied to our quantum system give rise to Galilean…

Quantum Physics · Physics 2015-06-15 U. Alvarez-Rodriguez , J. Casanova , L. Lamata , E. Solano

A key problem in the attempt to quantize the gravitational field is the choice of boundary conditions. These are mixed, in that spatial and normal components of metric perturbations obey different sets of boundary conditions. In the…

High Energy Physics - Theory · Physics 2007-05-23 Ivan G. Avramidi , Giampiero Esposito

Polymer quantum mechanics has been studied as a simplified picture that reflects some of the key properties of Loop Quantum Gravity; however, while the fate of relativistic symmetries in Loop Quantum Gravity is still not established, it is…

General Relativity and Quantum Cosmology · Physics 2017-12-06 Giovanni Amelino-Camelia , Michele Arzano , Malú Maira Da Silva , Daniel H. Orozco-Borunda

Homogeneous cosmological models with non-vanishing intrinsic curvature require a special treatment when they are quantized with loop quantum cosmological methods. Guidance from the full theory which is lost in this context can be replaced…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald , Ghanashyam Date , Kevin Vandersloot
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