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Related papers: Mapping Solutions in Nonmetricity Gravity: Investi…

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We consider the Brans-Dicke theory in non-metricity gravity, which belongs to the family of symmetric teleparallel scalar-tensor theories. Our focus lies in exploring the implications of the conformal transformation, as we derive the…

General Relativity and Quantum Cosmology · Physics 2023-10-26 Andronikos Paliathanasis

The 1+3 covariant approach and the covariant gauge-invariant approach to perturbations are used to analyze in depth conformal transformations in cosmology. Such techniques allow us to obtain very interesting insights on the physical content…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Sante Carloni , Emilio Elizalde , Sergei Odintsov

The issue of the equivalence between Jordan and Einstein conformal frames in scalar-tensor gravity is revisited, with emphasis on implementing running units in the latter. The lack of affine parametrization for timelike worldlines and the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Valerio Faraoni , Shahn Nadeau

In this work we study the Friedmann-Lema\^{i}tre-Robertson-Walker cosmologies with arbitrary spatial curvature for the symmetric teleparallel theories of gravity, giving the first presentation of their coincident gauge form. Our approach…

General Relativity and Quantum Cosmology · Physics 2025-01-24 Erik Jensko

An alternative interpretation of the conformal transformations of the metric is discussed according to which the latter can be viewed as a mapping among Riemannian and Weyl-integrable spaces. A novel aspect of the conformal transformation's…

General Relativity and Quantum Cosmology · Physics 2013-01-29 Israel Quiros , Ricardo Garcia-Salcedo , Jose Edgar Madriz Aguilar , Tonatiuh Matos

The conformal equivalence between Jordan frame and Einstein frame can be used in order to search for exact solutions in general theories of gravity in which scalar fields are minimally or nonminimally coupled with geometry. In the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Salvatore Capozziello , Ruggiero de Ritis , Alma Angela Marino

We investigate the cosmological aspects of the most general parity preserving Metric-Affine Gravity theory quadratic in torsion and non-metricity in the presence of a cosmological hyperfluid. The equations of motion are obtained by varying…

General Relativity and Quantum Cosmology · Physics 2022-01-13 Damianos Iosifidis , Lucrezia Ravera

We study teleparallel gravitational theories with are invariant under the conformal transformations. Wide family of the gravitational Lagrangians that are invariant under conformal transformations have investigated. Cosmological solutions…

General Relativity and Quantum Cosmology · Physics 2014-06-24 Davood Momeni , Ratbay Myrzakulov

In the context of the Relativistic Quantum Geometry formalism, where the cosmological constant is promoted to a dynamical variable by attributing it a geometric interpretation as a result of a flux on the boundary of a manifold and…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Juan Ignacio Musmarra , Claudia Moreno , Rafael Hernández-Jiménez

The debate on the physical relevance of conformal transformations can be faced by taking the Palatini approach into account to gravitational theories. We show that conformal transformations are not only a mathematical tool to disentangle…

High Energy Physics - Theory · Physics 2009-11-10 Gianluca Allemandi , Monica Capone , Salvatore Capozziello , Mauro Francaviglia

We use an alternative interpretation of quantum mechanics, based on the Bohmian trajectory approach, and show that the quantum effects can be included in the classical equation of motion via a conformal transformation on the background…

General Relativity and Quantum Cosmology · Physics 2019-11-20 G. Gregori , B. Reville , B. Larder

The existence of self-similar solutions is discussed in symmetric teleparallel $f(Q)$-theory for a Friedmann-Lema\^itre-Robertson-Walker background geometry with zero and non-zero spatial curvature. For the four distinct families of…

General Relativity and Quantum Cosmology · Physics 2022-12-01 N. Dimakis , M. Roumeliotis , A. Paliathanasis , P. S. Apostolopoulos , T. Christodoulakis

In recent years, the use of conformal transformation techniques has become widespread in the literature on gravitational theories alternative to general relativity, on cosmology, and on nonminimally coupled scalar fields. Typically, the…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Valerio Faraoni , Edgard Gunzig , Pasquale Nardone

Scalar-Tensor theories of gravity can be formulated in different frames, most notably, the Einstein and the Jordan one. While some debate still persists in the literature on the physical status of the different frames, a frame…

Astrophysics · Physics 2008-11-26 R. Catena , M. Pietroni , L. Scarabello

We focus on weak inhomogeneous models of the Universe at low redshifts, described by the Lema\^itre-Tolman-Bondi (LTB) metric. The principal aim of this work is to compare the evolution of inhomogeneous perturbations in the $\Lambda$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-20 Tiziano Schiavone , Giovanni Montani

We study the relation between the Jordan-Einstein frame transition and the possible description of the crossing of singularities in flat Friedmann universes, using the fact that the regular evolution in one frame can correspond to crossing…

General Relativity and Quantum Cosmology · Physics 2016-09-14 Alexander Yu. Kamenshchik , Ekaterina O. Pozdeeva , Sergey Yu. Vernov , Alessandro Tronconi , Giovanni Venturi

We investigate the dynamics and the phase-space evolution for the scalar nonmetricity cosmology with a Chameleon mechanism. In particular, we consider a spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker geometry and within the…

General Relativity and Quantum Cosmology · Physics 2024-07-09 Andronikos Paliathanasis

We study the evolution of the physical variables in $f\left( Q\right) $-gravity for two families of symmetric and flat connections in a spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker geometry where the equation of motion for the…

General Relativity and Quantum Cosmology · Physics 2023-05-16 Andronikos Paliathanasis

The discovery of the accelerated expansion of the universe highlighted General Relativity's inability to naturally account for dark energy without invoking a finely tuned cosmological constant. In response, a wide range of alternative…

General Relativity and Quantum Cosmology · Physics 2025-11-11 P. A. G. Monteiro , C. J. A. P. Martins

We present an exact analytical solution of the Einstein equations with cosmological constant in a spatially flat Robertson-Walker metric. This is interpreted as an isotropic Lemaitre-type version of the cosmological Friedmann model.…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Ion I. Cotaescu , Dumitru N. Vulcanov
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