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Related papers: A few cosmological implications of tensor nonlocal…

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In the macroscopic gravity approach to the averaging problem in cosmology, the Einstein field equations on cosmological scales are modified by appropriate gravitational correlation terms. We present exact cosmological solutions to the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 A. A. Coley , N. Pelavas , R. M. Zalaletdinov

In this chapter we review the recent developments of realizing $R^2$-like inflation in the framework of a most general UV nonlocal extension of Einstein's general theory of relativity (GR). It is a well-motivated robust approach towards…

High Energy Physics - Theory · Physics 2024-09-19 Alexey S. Koshelev , K. Sravan Kumar , Alexei A. Starobinsky

We consider some cosmological aspects of nonlocal modified gravity with $\Lambda$ term, where nonlocality is of the type $R \mathcal{F}(\Box) R$. Using ansatz of the form $\Box R = r R +s,$ we find a few a(t) nonsingular bounce cosmological…

General Relativity and Quantum Cosmology · Physics 2015-08-20 I. Dimitrijevic , B. Dragovich , J. Grujic , Z. Rakic

In this contribution I wish to address the question whether, and how, the global cosmological expansion influences local physics. I argue that a pseudo Newtonian picture can be quite accurate if "expansion" is taken to be an attribute of…

General Relativity and Quantum Cosmology · Physics 2014-09-10 Domenico Giulini

We introduce a cosmological model in the framework of Generalised Massive Gravity. This theory is an extension of non-linear massive gravity with a broken translation symmetry in the St\"uckelberg space. In a recent work, we showed the…

General Relativity and Quantum Cosmology · Physics 2020-11-25 Michael Kenna-Allison , A. Emir Gumrukcuoglu , Kazuya Koyama

We discuss the production and evolution of cosmological gravitons showing how the cosmological background affects their dynamics. Besides, the detection of cosmological gravitons could constitute an extremely important signature to…

General Relativity and Quantum Cosmology · Physics 2017-05-03 Salvatore Capozziello , Mariafelicia De Laurentis , Shin'ichi Nojiri , Sergei D. Odintsov

Investigations of the dynamic modes of the Poincare gauge theory of gravity found only two good propagating torsion modes; they are effectively a scalar and a pseudoscalar. Cosmology affords a natural situation where one might see…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Kun-Feng Shie , James M. Nester , Hwei-Jang Yo

A class of vector-tensor theories arises naturally in the framework of quadratic gravity in spacetimes with linear vector distortion. Requiring the absence of ghosts for the vector field imposes an interesting condition on the allowed…

High Energy Physics - Theory · Physics 2016-05-04 Jose Beltran Jimenez , Lavinia Heisenberg , Tomi S. Koivisto

In order to explain the late-time cosmological acceleration, we propose a new pure geometric gravity based on Deser-Woodard theory, in which the expansion of a matter-dominated universe can be accelerating. This new theory behaves as well…

General Relativity and Quantum Cosmology · Physics 2018-10-31 Shuxun Tian

General relativity and its cosmological solution predicts the existence of tensor modes of perturbations evolving on top of our Friedman-Lema\^itre-Robertson-Walker expanding Universe. Being gauge invariant and not necessarily coupled to…

General Relativity and Quantum Cosmology · Physics 2023-01-20 Amaury Micheli , Patrick Peter

Nonlocal modifications of gravity derive from corrections to the quantum gravitational stress tensor which grow nonperturbatively strong during primordial inflation and may persist to the current epoch. Phenomenological constructions have…

General Relativity and Quantum Cosmology · Physics 2026-05-01 C. Deffayet , R. P. Woodard

We consider cosmological models in scalar tensor theories of gravity that describe an accelerating universe, and we study a family of inverse power law potentials, for which exact solutions of the Einstein equations are known. We also…

Astrophysics · Physics 2009-11-13 M. Demianski , E. Piedipalumbo , C. Rubano , P. Scudellaro

Scalar-tensor theories are studied in the context of cosmological evolution, where the expansion history of the Universe is reconstructed. It is considered quintessence/phantom models, where inflation and cosmic acceleration are reproduced.…

High Energy Physics - Theory · Physics 2008-12-11 Diego Sáez-Gómez

Besides expanding anisotropically, the universe can also be anisotropic at the level of its (spatial) curvature. In particular, models with anisotropic curvature and isotropic expansion leads both to a $\Lambda$CDM-like phenomenology and to…

General Relativity and Quantum Cosmology · Physics 2017-11-17 Felipe O. Franco , Thiago S. Pereira

The observed acceleration of the Universe can be explained by modifying general relativity. One such attempt is the nonlocal model of Deser and Woodard. Here we fix the background cosmology using results from the Planck satellite and…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-05 Scott Dodelson , Sohyun Park

We consider extensions of General Relativity based on the non-local function $f(R, \Box^{-1} R)$, where $R$ is the Ricci curvature scalar and the non-locality is due to the term $\Box^{-1} R$. We focus on cosmological minisuperspaces and…

General Relativity and Quantum Cosmology · Physics 2022-01-19 Adriano Acunzo , Francesco Bajardi , Salvatore Capozziello

The scalar-tensor representation of nonlocally corrected gravity is considered. Some special solutions of the vacuum background equations were obtained that indicate to the nonequivalence of the initial theory and its scalar-tensor…

General Relativity and Quantum Cosmology · Physics 2015-05-13 N. A. Koshelev

Even though it is not possible to differentiate General Relativity from Teleparallel Gravity using classical experiments, it could be possible to discriminate between them by quantum gravitational effects. These effects have motivated the…

General Relativity and Quantum Cosmology · Physics 2017-10-17 Sebastian Bahamonde , Salvatore Capozziello , Mir Faizal , Rafael C. Nunes

We describe a general constitutive framework for a teleparallel extension of the general theory of relativity. This approach goes beyond the teleparallel equivalent of general relativity (TEGR) by broadening the analogy with the…

General Relativity and Quantum Cosmology · Physics 2024-04-12 Javad Tabatabaei , Shant Baghram , Bahram Mashhoon

We present a model of non-relativistic gravitational theory which is power-counting renormalizable in 3+1 dimensional spacetime. When applied to cosmology, the relativity-violation terms lead to a dark radiation component, which can give…

High Energy Physics - Theory · Physics 2009-11-13 Yi-Fu Cai , Emmanuel N. Saridakis