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Related papers: Mimetic Weyl geometric gravity

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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

We investigate the coupling of matter to geometry in conformal quadratic Weyl gravity, by assuming a coupling term of the form $L_m\tilde{R}^2$, where $L_m$ is the ordinary matter Lagrangian, and $\tilde{R}$ is the Weyl scalar. The coupling…

General Relativity and Quantum Cosmology · Physics 2022-03-30 Tiberiu Harko , Shahab Shahidi

We review recent developments in physical implications of Weyl conformal geometry. The associated Weyl quadratic gravity action is a gauge theory of the Weyl group of dilatations and Poincar\'e symmetry. Weyl conformal geometry is defined…

High Energy Physics - Theory · Physics 2025-06-05 D. M. Ghilencea

We investigate the possibility that the observed behavior of test particles outside galaxies, which is usually explained by assuming the existence of dark matter, is the result of the dynamical evolution of particles in a Weyl type…

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

We consider the recently introduced mimetic gravity, which is a Weyl-symmetric extension of the General Relativity and which can play a role of an imperfect fluid-like Dark Matter with a small sound speed. In this paper we discuss in…

General Relativity and Quantum Cosmology · Physics 2015-12-31 Katrin Hammer , Alexander Vikman

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

We discuss the concepts of Weyl and Riemann frames in the context of metric theories of gravity and state the fact that they are completely equivalent as far as geodesic motion is concerned. We apply this result to conformally flat…

General Relativity and Quantum Cosmology · Physics 2015-05-27 C. Romero , J. B. Fonseca-Neto , M. L. Pucheu

Weyl conformal geometry may play a role in early cosmology where effective theory at short distances becomes conformal. Weyl conformal geometry also has a built-in geometric Stueckelberg mechanism: it is broken spontaneously to Riemannian…

High Energy Physics - Theory · Physics 2020-02-19 D. M. Ghilencea

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

Metric-affine geometry provides a non-trivial extension of the general relativity where the metric and connection are treated as the two independent fundamental quantities in constructing the space-time (with non-vanishing torsion and…

General Relativity and Quantum Cosmology · Physics 2015-01-23 R. Vazirian , M. R. Tanhayi , Z. A. Motahar

We examine some Weyl invariant cosmological models in the framework of generalized dilaton gravity, in which the action is made of a set of $N$ conformally coupled scalar fields. It will be shown that when the FRW ansatz for the spacetime…

High Energy Physics - Theory · Physics 2015-06-23 Enrique Álvarez , Sergio González-Martin , Mario Herrero-Valea

The Weyl geometric gravity theory, in which the gravitational action is constructed from the square of the Weyl curvature scalar and the strength of the Weyl vector, has been intensively investigated recently. The theory admits a…

General Relativity and Quantum Cosmology · Physics 2025-11-19 Mohsen Khodadi , Tiberiu Harko

We study Weyl conformal geometry as a general gauge theory of the Weyl group (of Poincar\'e and dilatations symmetries) in a manifestly Weyl gauge covariant formalism in which this geometry is automatically metric and physically relevant.…

High Energy Physics - Theory · Physics 2025-03-31 C. Condeescu , D. M. Ghilencea , A. Micu

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

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

We investigate the field equations of the conformally invariant models of gravity with curvature-matter coupling, constructed in Weyl geometry, by using the Palatini formalism. We consider the case in which the Lagrangian is given by the…

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

We use Weyl connection and Weyl geometry in order to construct novel modified gravitational theories. In the simplest case where one uses only the Weyl-connection Ricci scalar as a Lagrangian, the theory recovers general relativity.…

General Relativity and Quantum Cosmology · Physics 2025-03-12 Gerasimos Kouniatalis , Emmanuel N. Saridakis

Weyl conformal geometry is a gauge theory of scale invariance that naturally brings together the Standard Model (SM) and Einstein gravity. The SM embedding in this geometry is possible without new degrees of freedom beyond SM and Weyl…

High Energy Physics - Theory · Physics 2025-02-14 D. M. Ghilencea

We investigate the cosmological evolution for the physical parameters in Weyl integrable gravity in a Friedmann--Lema\^{\i}tre--Robertson--Walker universe with zero spatially curvature. For the matter component, we assume that it is an…

General Relativity and Quantum Cosmology · Physics 2021-12-02 Andronikos Paliathanasis

We investigate the warm inflationary scenario in the Weyl geometric gravity theory, in which the action is constructed by adding matter to the simplest conformally invariant gravitational action in Weyl geometry. The $\tilde{R}^2$ theory…

General Relativity and Quantum Cosmology · Physics 2026-05-19 Runhua Huang , Tiberiu Harko , Shi-Dong Liang , Hong-Hao Zhang , Lei Ming
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