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Related papers: Conformal formulation of cosmological futures

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We perform a detailed dynamical analysis of various cosmological scenarios in extended (varying-mass) nonlinear massive gravity. Due to the enhanced freedom in choosing the involved free functions, this cosmological paradigm allows for a…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-05 Genly Leon , Joel Saavedra , Emmanuel N. Saridakis

Invited contribution to the Encyclopedia of Mathematical Physics (2nd edition), providing an overview over some main ideas and results in quantum cosmology. Key points: Canonical quantisation of homogeneous, isotropic cosmology; discussion…

General Relativity and Quantum Cosmology · Physics 2025-02-28 Steffen Gielen

Cosmology is undergoing an explosive period of activity, fueled both by new, accurate astrophysical data and by innovative theoretical developments. Cosmological parameters such as the total density of the Universe and the rate of…

Astrophysics · Physics 2007-05-23 A. S. Sakharov , H. Hofer

In the teleparallel framework of cosmology, a quintessence with non-minimal couplings to the scalar torsion and a boundary term is considered. A conformal coupling to matter density is also taken into account. It is shown that the model can…

General Relativity and Quantum Cosmology · Physics 2017-06-13 H. Mohseni Sadjadi

We explore the possibility of emergent cosmology using the effective potential formalism. We discover new models of emergent cosmology which satisfy the constraints posed by the cosmic microwave background (CMB). We demonstrate that, within…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Satadru Bag , Varun Sahni , Yuri Shtanov , Sanil Unnikrishnan

In this expository article we describe the attempt of defining cosmological singularities and we discuss their meaning in classical and quantum cosmology.

Popular Physics · Physics 2007-05-23 Giampiero Esposito

This paper explores exact cosmological solutions of anisotropic universe model through Noether symmetry technique in energy-momentum squared gravity. This theory resolves the primordial singularity and provides viable cosmological…

General Relativity and Quantum Cosmology · Physics 2023-05-24 M. Sharif , M. Zeeshan Gul

Based on the conjecture that rather than the second law of thermodynamics inevitably be breached as matter approaches a big crunch or a black hole singularity, the order of events should reverse, a model of the universe that resolves a…

General Physics · Physics 2007-05-23 Peter Lynds

The initial singularity is the most troubling feature of the standard cosmology, which quantum effects are hoped to resolve. In this paper, we study quantum cosmology with conformal (Weyl) invariant matter. We show it is natural to extend…

General Relativity and Quantum Cosmology · Physics 2017-05-24 Steffen Gielen , Neil Turok

We consider an evolution of anisotropic cosmological model on the example of the Bianchi type I homogeneous universe. It is filled by the mixture of matter and dark energy with an arbitrary barotropic equation of state (EoS). The general…

General Relativity and Quantum Cosmology · Physics 2023-06-14 S L Parnovsky

The detection of a time variation of the angle between two distant sources would reveal an anisotropic expansion of the Universe. We study this effect of "cosmic parallax" within the "ellipsoidal universe" model, namely a particular…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-29 L. Campanelli , P. Cea , G. L. Fogli , L. Tedesco

We consider the possibility to produce a bouncing universe in the framework of scalar-tensor gravity when the scalar field has a nonconformal coupling to the Ricci scalar. We prove that bouncing universes regular in the future with…

General Relativity and Quantum Cosmology · Physics 2016-06-01 B. Boisseau , H. Giacomini , D. Polarski

The condition for the vanishing of the Weyl tensor is integrated in the spherically symmetric case. Then, the resulting expression is used to find new, conformally flat, interior solutions to Einstein equations for locally anisotropic…

General Relativity and Quantum Cosmology · Physics 2015-06-25 L. Herrera , A. Di Prisco , J. Ospino , E. Fuenmayor

We present results on the non-linear dynamics of inhomogeneous cosmological models with irrotational dust and a positive cosmological constant, considering, in particular, a wide class with vanishing magnetic Weyl tensor. For those patches…

Astrophysics · Physics 2009-10-22 M. Bruni , S. Matarrese , O. Pantano

Motivated by the study of Weyl structures on conformal manifolds admitting parallel weightless forms, we define the notion of conformal product of conformal structures and study its basic properties. We obtain a classification of Weyl…

Differential Geometry · Mathematics 2019-01-08 Florin Belgun , Andrei Moroianu

Anisotropic cosmological models are constructed in $f(R,T)$ gravity theory to investigate the dynamics of universe concerning the late time cosmic acceleration. Using a more general and simple approach, the effect of the coupling constant…

General Physics · Physics 2018-10-05 B. Mishra , Sankarsan Tarai , S. K. Tripathy

We consider the problem of describing the asymptotic behaviour of \textsc{FRW} universes near their spacetime singularities in general relativity. We find that the Bel-Robinson energy of these universes in conjunction with the Hubble…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Spiros Cotsakis , Ifigeneia Klaoudatou

We present a model of the expanding Universe that begins in a zero energy vacuum state. The Universe results from the spontaneous breaking of the electroweak symmetry, wherein the vacuum with positive expectation energy produces the dark…

General Physics · Physics 2021-04-29 R. N. Henriksen

It is argued that a noncommutative geometry of spacetime leads to a reconciliation of electromagnetism and gravitation while providing an underpinning to Weyl's geometry. It also leads to a cosmology consistent with observation. A few other…

General Physics · Physics 2007-05-23 B. G. Sidharth

The evolution of a class of inhomogeneous spherically symmetric universe models possessing a varying cosmological term and a material fluid, with an adiabatic index either constant or not, is studied.

General Relativity and Quantum Cosmology · Physics 2015-06-25 Luis P. Chimento , Diego Pavon
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