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We present exact analytical solutions to the Conformal Weyl Gravity cosmological equations that are valid for both the matter and radiation dominated eras. The Primordial Nucleosynthesis process is also exhaustively studied. The main…

Astrophysics · Physics 2009-10-22 D. Elizondo , G. Yepes

The nature of the elusive dark matter can be probed by comparing the predictions of the cold dark matter framework with the gravitational field of massive galaxy clusters. However, a robust test of dark matter can only be achieved if the…

A simple modification to Einstein's theory of gravity in terms of a non-Riemannian connection is examined. A new tensor-variational approach yields field equations that possess a covariance similar to the gauge covariance of…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Robin W Tucker , Charles Wang

We revisit nonsingular cosmologies in which the limiting curvature hypothesis is realized. We study the cosmological perturbations of the theory and determine the general criteria for stability. For the simplest model, we find generic…

High Energy Physics - Theory · Physics 2017-08-08 Daisuke Yoshida , Jerome Quintin , Masahide Yamaguchi , Robert H. Brandenberger

General Relativity can be formulated in terms of a spatially Weyl invariant gauge theory called Shape Dynamics. Using this formulation, we establish a "bulk/bulk" duality between gravity and a Weyl invariant theory on spacelike Cauchy…

General Relativity and Quantum Cosmology · Physics 2013-01-23 Henrique Gomes , Sean Gryb , Tim Koslowski , Flavio Mercati

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 apply the conformal gravity theory to a sample of 111 spiral galaxies whose rotation curve data points extend well beyond the optical disk. With no free parameters other than galactic mass to light ratios, the theory is able to account…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Philip D. Mannheim , James G. O'Brien

We examine the peculiar velocity distribution function of galaxies in cosmological many-body gravitational clustering. Our statistical mechanical approach derives a previous basic assumption and generalizes earlier results to galaxies with…

Astrophysics · Physics 2009-11-10 Bernard Leong , William Saslaw

Recent research in the geometric formulation of quantum theory has implied that Weyl Geometry can be used to merge quantum theory and general relativity consistently as classical field theories. In the Weyl Geometric framework, it seems…

General Relativity and Quantum Cosmology · Physics 2021-12-28 Sijo K. Joseph

We present the BRST formalism of a Weyl conformal gravity in Weyl geometry. Choosing the extended de Donder gauge-fixing condition (or harmonic gauge condition) for the general coordinate invariance and the new scalar gauge-fixing for the…

High Energy Physics - Theory · Physics 2022-11-23 Ichiro Oda , Philipp Saake

In the multiscalar-metric frameworks, the issues of the vacuum energy/cosmological constant (CC) screening due to the Weyl-scale enhancement of the Diff gauge symmetry, along with emergence of the massive dark gravity components through the…

General Relativity and Quantum Cosmology · Physics 2025-03-03 Yury F. Pirogov

In AdS/CFT, the holographic Weyl anomaly computation relates the a-anomaly coefficient to the properties of the bulk action at the UV fixed point. This universal behavior suggests the possibility of a holographic c-theorem for the a-anomaly…

High Energy Physics - Theory · Physics 2013-05-30 James T. Liu , Wafic Sabra , Zhichen Zhao

We present an analysis of the classic wormhole geometries based on conformal Weyl gravity, rather than standard general relativity. The main characteristics of the resulting traversable wormholes remain the same as in the seminal study by…

General Relativity and Quantum Cosmology · Physics 2016-05-26 Gabriele U. Varieschi , Kellie L. Ault

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 explore the cosmological viability of a theory of gravity defined by the Lagrangian $f(\mathcal{R})=\mathcal{R}^{n\left(\mathcal{R}\right)}$ in the Palatini formalism, where $n\left(\mathcal{R}\right)$ is a dimensionless function of the…

General Relativity and Quantum Cosmology · Physics 2021-05-05 Daniel Coumbe

We examine the Weyl anomaly for a four-dimensional z=3 Lifshitz scalar coupled to Horava's theory of anisotropic gravity. We find a one-loop break-down of scale-invariance at second order in the gravitational background.

High Energy Physics - Theory · Physics 2009-12-04 Ido Adam , Ilarion V. Melnikov , Stefan Theisen

Most Milky Way globular clusters (GCs) exhibit measurable flattening, even if on a very low level. Both cluster rotation and tidal fields are thought to cause this flattening. Nevertheless, rotation has only been confirmed in a handful of…

Recent measurements from the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT) have placed the strictest constraints on the primordial scalar perturbation spectrum, reporting a spectral index of $n_s\sim0.967-0.98$ at 95%…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-09 Qing-Yang Wang

We point out a new phenomenon which seems to be generic in 4d effective theories of scalar fields coupled to Einstein gravity, when applied to cosmology. A lift of such theories to a Weyl-invariant extension allows one to define classical…

High Energy Physics - Theory · Physics 2015-06-03 Itzhak Bars , Shih-Hung Chen , Paul J. Steinhardt , Neil Turok

We discuss Weyl (conformal) transformations in two-dimensional matterless dilaton gravity. We argue that both classical and quantum dilaton gravity theories are invariant under Weyl transformations.

High Energy Physics - Theory · Physics 2009-10-31 Marco Cavaglia