English
Related papers

Related papers: Flatly Foliated Relativity

200 papers

Faddeev variant of embedding theory is an example of using the embedding approach for the description of gravity. In the original form of the embedding approach, the gravity is described by an embedding function of a four-dimensional…

General Relativity and Quantum Cosmology · Physics 2021-12-21 S. S. Kuptsov , S. A. Paston

We exploit an arbitrary extrinsic time foliation of spacetime to solve the constraints in spherically symmetric general relativity. Among such foliations there is a one parameter family, linear and homogeneous in the extrinsic curvature,…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Jemal Guven , Niall O Murchadha

In a scalar-coupled-gravity model, the quadratically divergent counter term appearing in the mass renormalization of the scalar fields must inherit corrections arising out of gravitational interactions. In this work we have explicitly…

General Relativity and Quantum Cosmology · Physics 2020-09-15 Sumanta Chakraborty

The Friedman-Lemaitre-Robertson-Walker (FLRW) cosmological models are based on the assumptions of large-scale homogeneity and isotropy of the distribution of matter and energy. They are usually taken to have spatial sections that are simply…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Helio V. Fagundes

Modifications to gravity that add additional functions of the Ricci curvature to the Einstein-Hilbert action -- collectively known as $f(R)$ theories -- have been studied in great detail. When considered as complete theories of gravity they…

Astrophysics · Physics 2009-02-20 Simon DeDeo , Dimitrios Psaltis

This is a survey of a new type of relativistic space-time framework; the so-called quasi-metric framework. The basic geometric structure underlying quasi-metric relativity is quasi-metric space-time; this is defined as a 4-dimensional…

General Relativity and Quantum Cosmology · Physics 2024-03-20 Dag Østvang

An extremely simple and unified base for physics comes out by starting all over from a single postulate on the common nature of matter and stationary forms of radiation quanta. Basic relativistic, gravitational (G) and quantum mechanical…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Rafael A. Vera

The gravitational equations were derived in general relativity (GR) using the assumption of their covariance relative to arbitrary transformations of coordinates. It has been repeatedly expressed an opinion over the past century that such…

General Relativity and Quantum Cosmology · Physics 2024-08-07 Alexander P. Sobolev

The standard cosmological model, rooted in General Relativity (GR), has achieved remarkable success, yet it still faces unresolved issues like the nature of dark matter, dark energy, and the Hubble tension. These challenges might imply the…

General Relativity and Quantum Cosmology · Physics 2025-05-13 Valentina Danieli , Antonio De Felice

For higher-derivative f(R) gravity where R is the Ricci scalar, a class of models is proposed which produce viable cosmology different from the LambdaCDM one at recent times and satisfy cosmological, Solar system and laboratory tests. These…

Astrophysics · Physics 2009-07-09 Alexei A. Starobinsky

Extended gravitational models have gained large attention in the last couple of decades. In this work, we examine the solution space of vacuum, static, and spherically symmetric spacetimes within $F(R)$ theories, introducing novel methods…

General Relativity and Quantum Cosmology · Physics 2024-11-11 Cristobal Laporte , Agustín Silva

A scalar, preferred-frame theory of gravitation is summarized. Space-time is endowed with both a flat metric and a curved, "physical" metric. Motion is governed by a natural extension of Newton's second law, which implies geodesic motion…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Mayeul Arminjon

We revisit the evolution of the scale factor in a flat FRW spacetime with a new generalized decay rule for the dynamic $\Lambda$-term under modified theories of gravity. It analyses certain cosmological parameters and examines their…

General Physics · Physics 2021-08-02 Anirudh Pradhan , De Avik , Tee How Loo , D. C. Maurya

In the context of a recently proposed nonlinear massive gravity with Lorentz-invariant mass terms, we investigate open Friedmann-Robertson-Walker (FRW) universes driven by arbitrary matter source. While the flat FRW solutions were recently…

High Energy Physics - Theory · Physics 2015-03-12 A. Emir Gumrukcuoglu , Chunshan Lin , Shinji Mukohyama

The physical non-existence of gravitational waves (GW's) as a consequence of the non-existence in general relativity (GR) of physically privileged reference frames, and of the ``plasticity'' of relativistic notion of a coordinate system.

General Physics · Physics 2007-09-05 Angelo Loinger

The consequence of energy conservation in the flat Friedmannn-Robertson-Walker (FRW) cosmology is a strictly positive accelerating expansion. A mechanism is proposed for this expansion due to the effect of the attractive (negative)…

General Relativity and Quantum Cosmology · Physics 2009-01-09 Steven Maxson

In a recent paper [1], it was introduced a new class of gravitational theories with two local degrees of freedom. The existence of these theories apparently challenges the distinctive role of general relativity as the unique non-linear…

General Relativity and Quantum Cosmology · Physics 2018-10-30 Raúl Carballo-Rubio , Francesco Di Filippo , Stefano Liberati

A new, very different physical model of the universe is proposed. Its virtues include unifying relativity and quantum mechanics, and particles with de Broglie waves. It also appears to provide a truly unified physical basis for…

General Physics · Physics 2008-02-03 Ben Kristoffen

We study FRW homogeneous cosmological solutions in the recently found ghost free massive gravity. In previous works it was shown that when the additional extra metric, needed to generate the mass term, is taken as non-dynamical and flat, no…

High Energy Physics - Theory · Physics 2012-05-21 D. Comelli , M. Crisostomi , F. Nesti , L. Pilo

The extension of the so-called "empty" (with gravity and antigravity that compensate each other in full or do not exist at all) universe and cosmological redshift in it are considered in this paper. Its flat space-time can be submitted not…

Astrophysics · Physics 2007-05-23 Leonid S. Sitnikov