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We study inflationary dynamics using a recently introduced classical-quantum correspondence for investigating the backreaction of a quantum mechanical degree of freedom to a classical background. Using specifically a coupled…

General Relativity and Quantum Cosmology · Physics 2021-11-15 Reginald Christian Bernardo

We derive the first quantum gravitational corrections to the inflationary power spectra for a general single-field scalar-tensor theory which includes a non-minimal coupling to gravity, a non-standard scalar kinetic term and an arbitrary…

General Relativity and Quantum Cosmology · Physics 2020-01-08 Christian F. Steinwachs , Matthijs L. van der Wild

We study corrections to the power spectra of curvature and tensor perturbations and the tensor-to-scalar ratio in single field slow roll inflation due to initial conditions imprinted by a fast-roll stage prior to slow roll. For a wide range…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-22 Louis Lello , Daniel Boyanovsky

Quadratic gravity is a fourth-order (in derivatives) theory that can serve as an attractive upgrade to the standard description of gravity provided by General Relativity, thanks to its renormalizability and its built-in description of…

General Relativity and Quantum Cosmology · Physics 2025-05-30 Jisuke Kubo , Jeffrey Kuntz

The primordial spectrum of cosmological tensor perturbations is considered as a possible probe of quantum gravity effects. Together with string theory, loop quantum gravity is one of the most promising frameworks to study quantum effects in…

General Relativity and Quantum Cosmology · Physics 2009-04-09 J. Grain , A. Barrau

We compute the rate with which super-Hubble cosmological fluctuations are decohered during inflation, by their gravitational interactions with unobserved shorter-wavelength scalar and tensor modes. We do so using Open Effective Field Theory…

High Energy Physics - Theory · Physics 2023-07-12 C. P. Burgess , R. Holman , Greg Kaplanek , Jerome Martin , Vincent Vennin

We study perturbative noncommutative quantum gravity by expanding the gravitational field about a fixed classical background. A calculation of the one loop gravitational self-energy graph reveals that only the non-planar graviton loops are…

High Energy Physics - Theory · Physics 2009-10-31 J. W. Moffat

We have estimated higher order quantum gravity corrections to de~Sitter spacetime. Our results suggest that, while the classical spacetime metric may be distorted by the graviton self-interactions, the corrections are relatively weaker than…

General Relativity and Quantum Cosmology · Physics 2009-10-22 A. D. Dolgov , M. B. Einhorn , V. I. Zakharov

Precise cosmological data from WMAP and forthcoming CMB experiments motivate the study of the quantum corrections to the slowroll inflationary parameters.We find the quantum (loop) corrections to the equations of motion of the classical…

Astrophysics · Physics 2009-11-10 D. Boyanovsky , H. J. de Vega , N. G. Sanchez

Inhomogeneous cosmological perturbation equations are derived in loop quantum gravity, taking into account corrections in particular in gravitational parts. This provides a framework for calculating the evolution of modes in structure…

The scenario of constant-roll inflation is studied where the inflaton is a scalar field with modified kinetic term, known as non-canonical scalar field. This modification leads to some changes in the slow-roll parameters, and also by taking…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-23 Abolhassan Mohammadi , Khaled Saaidi , Haidar Sheikhahmadi

In order to go beyond the mean-field approximation, commonly used in the inflationary computations, an identification of the quantum constituents of the inflationary background is made. In particular, the homogeneous scalar field…

High Energy Physics - Theory · Physics 2017-03-08 Lasha Berezhiani

The dependence of cosmological and inflationary parameters on time during the last 60 e-folds in inflation is investigated using a slow-roll inflation model. The time dependence of the inflaton field is calculated for the case of chaotic…

Astrophysics · Physics 2008-12-15 Shiro Hirai , Tomoyuki Takami

We calculate power spectra of cosmological perturbations at high accuracy for two classes of inflation models. We classify the models according to the behaviour of the Hubble distance during inflation. Our approximation works if the Hubble…

Astrophysics · Physics 2009-11-06 Dominik J. Schwarz , Cesar A. Terrero-Escalante , Alberto A. Garcia

After a brief review of the different approaches to predict the possible quantum gravity corrections to quantum field theory, we discuss in some detail the formulation based on a Gaussian reference frame fixing. Then, we implement this…

General Relativity and Quantum Cosmology · Physics 2023-06-12 Giulia Maniccia , Giovanni Montani , Leonardo Torcellini

In this article, we explore the concept of cosmological inflation within the framework of the $f (T,\mathcal{T})$ theory of gravity, where $f$ is a general function of the Torsion scalar $T$ and the trace, $\mathcal{T}$, of the…

General Relativity and Quantum Cosmology · Physics 2023-11-14 Aaqid Bhat , Sanjay Mandal , P. K. Sahoo

At the level of heuristic effective dynamics, we investigate the cosmological inflation with holonomy corrections of loop quantum cosmology (LQC) in the $k=0$ Friedmann-Robertson-Walker model with a single inflaton field subject to a simple…

General Relativity and Quantum Cosmology · Physics 2010-04-29 Dah-Wei Chiou , Kai Liu

We develop a worldline approach to quantum gravity in D=4. Using the background field method we consider the covariantly gauge fixed Einstein-Hilbert action with cosmological constant, and find a worldline representation of the differential…

High Energy Physics - Theory · Physics 2013-06-25 Fiorenzo Bastianelli , Roberto Bonezzi

We deduce, in a general background gauge, the counter-term Lagrangian for pure quantum gravity to one-loop order. As an application, we evaluate the leading quantum correction to the classical gravitational potential, generated by the…

High Energy Physics - Theory · Physics 2022-09-13 F. T. Brandt , J. Frenkel , D. G. C. McKeon

We extend our investigation of soft graviton effects on the microscopic dynamics of matter fields in de Sitter space. We evaluate the quantum equation of motion in generic gauge theories. We find that the Lorentz invariance can be respected…

High Energy Physics - Theory · Physics 2013-06-14 Hiroyuki Kitamoto , Yoshihisa Kitazawa