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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

It has been suggested that the observed flat rotation curves of disk galaxies can be a peculiar effect of General Relativity (GR) rather than evidence for the presence of dark matter (DM) halos in Newtonian gravity. In Ciotti (2022) the…

Astrophysics of Galaxies · Physics 2023-04-14 Luca Ciotti

Just after Weyl's paper (Weyl in Gravitation und Elektrizit\"at, Sitzungsber. Preuss. Akad., Berlin, 1918) Einstein claimed that a gravity model written in a spacetime geometry with non-metricity suffers from a phenomenon, the so-called…

General Relativity and Quantum Cosmology · Physics 2023-01-18 Caglar Pala , Ozcan Sert , Muzaffer Adak

This paper is a sequel to the author's paper entitled "On Dark Matter, Spiral Galaxies, and the Axioms of General Relativity" [arXiv:1004.4016] which explored a geometrically natural axiomatic definition for dark matter modeled by a scalar…

General Physics · Physics 2012-12-27 Hubert L. Bray

A very general class of axially-symmetric metrics in general relativity (GR) that includes rotations is used to discuss the dynamics of rotationally-supported galaxies. The exact vacuum solutions of the Einstein equations for this extended…

General Relativity and Quantum Cosmology · Physics 2023-02-15 Yogendra Srivastava , Giorgio Immirzi , John Swain , Orland Panella , Simone Pacetti

We obtain exact black hole solutions for static and spherically symmetric sources in a Weyl conformal gauge theory of gravity. We consider a quadratic gravitational action built from the Weyl tensor within a dilation geometry. In a…

General Relativity and Quantum Cosmology · Physics 2025-09-29 Leandro A. Lessa , Caio F. B. Macedo , Manoel M. Ferreira

When the full connection of Weyl conformal gravity is varied instead of just the metric, the resulting vacuum field equations reduce to the vacuum Einstein equation, up to the choice of local units, if and only if the torsion vanishes. This…

General Relativity and Quantum Cosmology · Physics 2014-07-30 James T. Wheeler

We investigate a static solution with spherical symmetry of a recently proposed field theory of gravitation. In this so-called NDL theory, matter interacts with gravity in accordance with the Weak Equivalence Principle, while gravitons have…

General Relativity and Quantum Cosmology · Physics 2009-11-07 M. Novello , S. E. Perez Bergliaffa , K. E. Hibberd

Mimetic gravity is a Weyl-symmetric extension of General Relativity, related to the latter by a singular disformal transformation, wherein the appearance of a dust-like perfect fluid can mimic cold dark matter at a cosmological level.…

General Relativity and Quantum Cosmology · Physics 2017-03-03 L. Sebastiani , S. Vagnozzi , R. Myrzakulov

A mysterious dark matter is supposed to exist in the galactic halos. In this contrast, we discuss the possibility of explaining the flat rotational velocity curves in f(R) gravity by solving field equations numerically in vacuum and for…

General Physics · Physics 2021-03-30 Muhammad Usman

Using Penrose diagrams the causal structure of the static spherically symmetric vacuum solution to conformal (Weyl) gravity is investigated. A striking aspect of the solution is an unexpected physical singularity at $r=0$ caused by a linear…

Astrophysics · Physics 2009-09-25 A. Edery , M. B. Paranjape

We apply the Weyl method, as sanctioned by Palais' symmetric criticality theorems, to obtain those -highly symmetric -geometries amenable to explicit solution, in generic gravitational models and dimension. The technique consists of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S. Deser , Bayram Tekin

This paper presents three aspects by which the Weyl geometric generalization of Riemannian geometry, and of Einstein gravity, sheds light on actual questions of physics and its philosophical reflection. After introducing the theory's…

General Relativity and Quantum Cosmology · Physics 2015-07-28 Erhard Scholz

It has been claimed in I. Arraut, 2023 EPL 144 29003 [arXiv:2311.05652] that General Relativity can generate effects equivalent to dark matter, based on a "new modified symmetry that emerges at galactic scale". We show that (i) the…

General Relativity and Quantum Cosmology · Physics 2024-04-05 L. Filipe O. Costa , F. Frutos-Alfaro , José Natário , Michael Soffel

The Weyl double copy is a relationship between classical solutions in gauge and gravity theories, and has previously been applied to vacuum solutions in both General Relativity and its generalisations. There have also been suggestions that…

High Energy Physics - Theory · Physics 2024-07-26 Kymani Armstrong-Williams , Nathan Moynihan , Chris D. White

Motivated by an axiomatic approach to characterize space-time it is investigated a reformulation of Einstein's gravity where the pseudo-riemannian geometry is substituted by a Weyl one. It is presented the main properties of the Weyl…

General Relativity and Quantum Cosmology · Physics 2011-12-19 F. P. Poulis , J. M. Salim

The Bach equation, i.e., the vacuum field equation following from the Lagrangian L=C_{ijkl}C^{ijkl}, will be completely solved for the case that the metric is conformally related to the cartesian product of two 2-spaces; this covers the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 V. Dzhunushaliev , H. -J. Schmidt

Recently, the static spherically symmetric solution of the gravitational field equations have been found in theories describing massive graviton with spontaneous breaking of the Lorentz invariance. These solutions, which show off two…

General Relativity and Quantum Cosmology · Physics 2009-05-07 Michael V. Bebronne

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