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In this essay we offer a comprehensible overview of the gravitational aether scenario. This is a possible extension of Einstein's theory of relativity to the quantum regime via an effective approach. Quantization of gravity usually faces…

General Relativity and Quantum Cosmology · Physics 2017-05-19 Michael Florian Wondrak

We investigate the cosmology of a recently proposed deformation of Einstein gravity, emerging from quantum gravity heuristics. The theory is constructed to have de Sitter space as a vacuum solution, and thus to be relevant to the…

Quintessence issues can be achieved by taking into account higher order curvature invariants into the effective action of gravitational field. Such an approach is naturally related to fundamental theories of quantum gravity which predict…

Astrophysics · Physics 2009-11-10 S. Capozziello , V. F. Cardone , S. Carloni , A. Troisi

We study the dynamics of the homogeneous and isotropic cosmological background in the recently proposed ``quantum phenomenological gravitational dynamics'', characterised by logarithmic corrections to the Bekenstein entropy. We show that…

General Relativity and Quantum Cosmology · Physics 2023-07-21 Marco de Cesare , Giulia Gubitosi

Although the current galaxy models yield calculations consistent with much of the data, many irregularities exist, exceptions have been found to the current models, the $\Lambda$CDM model apparently fails on galaxy scales, dark matter…

Astrophysics · Physics 2007-05-23 John C. Hodge

Combining cosmological probes has consolidated the standard cosmological model with percent precision, but some tensions have recently emerged when certain parameters are estimated from the local or primordial Universe. The origin of this…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-16 Fabrizio Cogato , Michele Moresco , Lorenzo Amati , Andrea Cimatti

We study the implications of a combined analysis of cosmic standard candles and standard rulers on the viability of cosmological models beyond the cosmological concordance model. To this end, we employ well-established data in the form of…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-19 Manfred Lindner , Kevin Max , Moritz Platscher , Jonas Rezacek

We construct a phenomenological theory of gravitation based on a second order gauge formulation for the Lorentz group. The model presents a long-range modification for the gravitational field leading to a cosmological model provided with an…

General Relativity and Quantum Cosmology · Physics 2011-02-09 R. R. Cuzinatto , C. A. M. de Melo , L. G. Medeiros , P. J. Pompeia

In cosmology, the analysis of observational evidence is very important to test theoretical models of the Universe. Artificial neural networks are powerful and versatile computational tools for data modelling and are recently being…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-15 Juan de Dios Rojas Olvera , Isidro Gómez-Vargas , J. Alberto Vázquez

In this paper, we carry out a study of viable cosmological models in $f(R)$-gravity at the background level. We use observable parameters like $\Omega$ and $\gamma$ to form autonomous system of equations and show that the models under…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-28 Amna Ali , Radouane Gannouji , M. Sami , Anjan A. Sen

Nonlocal cosmological models are studied extensively in recent times because of their interesting cosmological consequences. In this paper, we have analyzed background cosmology on a class of non-local models which are motivated by the…

General Relativity and Quantum Cosmology · Physics 2020-01-08 Utkarsh Kumar , Sukanta Panda

A scalar-tensor theory of gravity can be made not only to account for the current cosmic acceleration, but also to satisfy solar-system and laboratory constraints, by introducing a non-linear derivative interaction for the scalar field.…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Tsutomu Kobayashi , Hiroyuki Tashiro , Daichi Suzuki

(abridged) Gravitationally lensed quasars can be used as powerful cosmological and astrophysical probes. We can (i) infer the Hubble constant based on the time-delay technique, (ii) unveil substructures along the l.o.s. toward distant…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-05 D. Sluse , V. Chantry , P. Magain , F. Courbin , G. Meylan

Cosmography can be considered as a sort of a model-independent approach to tackle the dark energy/modified gravity problem. In this review, the success and the shortcomings of the $\Lambda$CDM model, based on General Relativity and standard…

General Relativity and Quantum Cosmology · Physics 2019-04-09 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

In this work we consider gravitational theories in which the effect of coupling characteristic classes, appropriately introduced as operators in the Einstein-Hilbert action, has been taken into account. As it is well known, this approach…

General Relativity and Quantum Cosmology · Physics 2016-07-29 J. Lorca Espiro , Yerko Vásquez

Bimetric gravity is an interesting alternative to standard GR given its potential to provide a concrete theoretical framework for a ghost-free massive gravity theory. Here we investigate a class of Bimetric gravity models for their…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 Ajay Bassi , Shahnawaz A. Adil , Manvendra Pratap Rajvanshi , Anjan A. Sen

Studies of galaxy clusters have proved crucial in helping to establish the standard model of cosmology, with a universe dominated by dark matter and dark energy. A theoretical basis that describes clusters as massive, multi-component,…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-26 Steven W. Allen , August E. Evrard , Adam B. Mantz

Since the discovery of the accelerated expansion of the present Universe, significant theoretical developments have been made in the area of modified gravity. In the meantime, cosmological observations have been providing more high-quality…

Over the past decades, advancements in observational cosmology have introduced us in an era of precision cosmology, dramatically enhancing our understanding of the Universe's history as well as bringing new tensions to light. Observations…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-24 Matteo Forconi

Inflation is an early period of accelerated cosmic expansion, thought to be sourced by high energy physics. A key task today is to use the influx of increasingly precise observational data to constrain the plethora of inflationary models…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-05 Joseph Elliston