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We discuss the cosmological evolution of the Weyl conformal geometry and its associated Weyl quadratic gravity. The Einstein gravity (with a positive cosmological constant) is recovered in the spontaneously broken phase of Weyl gravity;…

General Relativity and Quantum Cosmology · Physics 2022-06-24 D. M. Ghilencea , T. Harko

We apply singularity analysis to investigate the integrability properties of the gravitational field equations in Weyl Integrable Spacetime for a spatially flat Friedmann--Lema\^itre--Robertson--Walker background spacetime induced with an…

General Relativity and Quantum Cosmology · Physics 2022-06-28 Andronikos Paliathanasis

We consider a cosmological model in a Friedmann--Lema\^{\i}tre--Robertson--Walker background space with an ideal gas defined in Weyl Integrable gravity. In the Einstein-Weyl theory a scalar field is introduced in a geometric way.…

General Relativity and Quantum Cosmology · Physics 2022-08-24 Andronikos Paliathanasis

We investigated the possibility of the homogeneous and isotropic cosmological solution in Weyl geometry, which differs from the Riemannian geometry by adding the so called Weyl vector. The Weyl gravity is obtained by constructing the…

General Relativity and Quantum Cosmology · Physics 2022-12-06 V. A. Berezin , V. I. Dokuchaev

We derive a Weyl invariant equation for Gravity by gauging the global Weyl invariance of vacuum Einstein equations. The equation is linear in the curvature and a natural generalization of Einstein equations to Weyl geometry. The system has…

General Relativity and Quantum Cosmology · Physics 2024-12-03 Máximo Bañados

We consider a spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker background space with an ideal gas and a multifield Lagrangian consisting of two minimally coupled scalar fields which evolve in a field space of constant curvature.…

General Relativity and Quantum Cosmology · Physics 2022-02-23 Alex Giacomini , Esteban González , Genly Leon , Andronikos Paliathanasis

In this paper we explore the physical consequences of assuming Weyl invariance of the laws of gravity from the classical standpoint exclusively. Actual Weyl invariance requires to replace the underlying Riemannian geometrical structure of…

General Relativity and Quantum Cosmology · Physics 2020-04-20 Israel Quiros

We show how to lift a generic non-scale invariant action in Einstein frame into a locally conformally-invariant (or Weyl-invariant) theory and present a new general form for Lagrangians consistent with Weyl symmetry. Advantages of such a…

High Energy Physics - Theory · Physics 2014-02-26 Itzhak Bars , Paul Steinhardt , Neil Turok

We investigated the possibility of construction the homogeneous and isotropic cosmological solutions in Weyl geometry. We derived the self-consistency condition which ensures the conformal invariance of the complete set of equations of…

General Relativity and Quantum Cosmology · Physics 2021-12-01 Victor A. Berezin , Vyacheslav I. Dokuchaev , Yury N. Eroshenko , Alexey L. Smirnov

We consider cosmological implications of the Weyl geometric gravity theory. The basic action of the model is obtained from the simplest conformally invariant gravitational action, constructed, in Weyl geometry, from the square of the Weyl…

General Relativity and Quantum Cosmology · Physics 2024-11-18 Tiberiu Harko , Shahab Shahidi

This article analyzes the present anomalies of cosmology from the point of view of integrable Weyl geometry. It uses P.A.M. Dirac's proposal for a weak extension of general relativity, with some small adaptations. Simple models with…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Erhard Scholz

We study the evolution of time-like congruences in the vacuum solutions of Weyl conformal theory of gravity. Using the Raycaudhuri equation, we show that for positive values of the coeffcient of the linear term in the solution and in the…

General Relativity and Quantum Cosmology · Physics 2016-02-03 Morteza Mohseni , Mohsen Fathi

A scale invariant, Weyl geometric, Lagrangian approach to cosmology is explored, with a a scalar field phi of (scale) weight -1 as a crucial ingredient besides classical matter \cite{Tann:Diss,Drechsler:Higgs}. For a particularly simple…

Astrophysics · Physics 2009-11-18 Erhard Scholz

In this paper we revisit the motivation and construction of a unified theory of gravity and electromagnetism, following Weyl's insights regarding the appealing potential connection between the gauge invariance of electromagnetism and the…

General Relativity and Quantum Cosmology · Physics 2018-02-13 Carlos Barceló , Raúl Carballo-Rubio , Luis J. Garay

We consider a mimetic type extension of the Weyl geometric gravity theory, by assuming that the metric of the space-time manifold can be parameterized in terms of a scalar field, called the mimetic field. The action of the model is obtained…

General Relativity and Quantum Cosmology · Physics 2025-03-19 Daria-Ioana Visa , Tiberiu Harko , Shahab Shahidi

We provide a gauge-invariant theory of gravitation in the context of Weyl Integrable Space-Times. After making a brief review of the theory's postulates, we carefully define the observers' proper-time and point out its relation with…

General Relativity and Quantum Cosmology · Physics 2014-10-31 F. P. Poulis , J. M. Salim

We consider an $f(Q,T)$ type gravity model in which the scalar non-metricity $Q_{\alpha \mu \nu}$ of the space-time is expressed in its standard Weyl form, and it is fully determined by a vector field $w_{\mu}$. The field equations of the…

General Relativity and Quantum Cosmology · Physics 2024-11-18 Yixin Xu , Tiberiu Harko , Shahab Shahidi , Shi-Dong Liang

We consider numerical black hole solutions in the Weyl conformal geometry, and its associated conformally invariant Weyl quadratic gravity. In this model Einstein gravity (with a positive cosmological constant) is recovered in the…

General Relativity and Quantum Cosmology · Physics 2024-11-18 Jin-Zhao Yang , Shahab Shahidi , Tiberiu Harko

In this work, we study the issue of the past and future cosmological singularities in the context of the fourth-order conformal Weyl gravity. In particular, we investigate the emergent universe scenario proposed by Ellis {\it et al}, and…

General Relativity and Quantum Cosmology · Physics 2020-06-02 Yaghoub Heydarzade

In this paper we apply the symmetry principle in order to search for an alternative unified explanation of several cosmological puzzles such as the present stage of accelerated expansion of the Universe and the Hubble tension issue, among…

General Relativity and Quantum Cosmology · Physics 2023-01-13 Israel Quiros
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