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A four-dimensional black hole solution of the Einstein equations with a positive cosmological constant, coupled to a conformal scalar field, is given. There is a curvature singularity at the origin, and scalar field diverges inside the…

High Energy Physics - Theory · Physics 2009-11-07 Cristian Martinez , Ricardo Troncoso , Jorge Zanelli

Although cosmological solutions to Einstein's equations are known to be generically singular, little is known about the nature of singularities in typical spacetimes. It is shown here how the operator splitting used in a particular…

General Relativity and Quantum Cosmology · Physics 2009-10-22 B. K. Berger , V. Moncrief

We consider a theory of gravity with a hidden extra-dimension and metric-dependent torsion. A set of physically motivated constraints are imposed on the geometry so that the torsion stays confined to the extra-dimension and the…

General Relativity and Quantum Cosmology · Physics 2013-05-30 Karthik H. Shankar , Anand Balaraman , Kameshwar C. Wali

This paper invokes a new mechanism for reducing a coupled system of fields (including Einstein's equations without a cosmological constant) to equations that possess solutions exhibiting characteristics of immediate relevance to current…

General Relativity and Quantum Cosmology · Physics 2019-11-05 Robin W. Tucker , Timothy J. Walton , Manuel Arrayás , José L. Trueba

The action for gravity and the standard model includes, as well as the positive energy fermion and boson fields, negative energy fields. The Hamiltonian for the action leads through a positive and negative energy symmetry of the vacuum to a…

High Energy Physics - Theory · Physics 2007-05-23 J. W. Moffat

In this paper we provide both a diagnosis and resolution of the cosmological constant problem, one in which a large (as opposed to a small) cosmological constant $\Lambda$ can be made compatible with observation. We trace the origin of the…

Astrophysics · Physics 2009-10-31 Philip D. Mannheim

A class of cosmological solutions of higher dimensional Einstein field equations with the energy-momentum tensor of a homogeneous, isotropic fluid as the source are considered with an anisotropic metric that includes the direct sum of a…

General Relativity and Quantum Cosmology · Physics 2013-10-24 Ozgur Akarsu , Tekin Dereli

We study the solutions of the semiclassical Einstein equation in flat cosmological spacetimes driven by a massive conformally coupled scalar field. In particular, we show that it is possible to give initial conditions at finite time to get…

Mathematical Physics · Physics 2015-03-10 Nicola Pinamonti , Daniel Siemssen

We describe a simple gauge-fixing that leads to a construction of a quantum Hilbert space for quantum gravity in an asymptotically Anti de Sitter spacetime, valid to all orders of perturbation theory. The construction is motivated by a…

High Energy Physics - Theory · Physics 2023-06-28 Edward Witten

In this work, we investigate the $n$-dimensional charged static black hole solutions in the Einstein-\ae ther theory. By taking the metric parameter $k$ to be $1,0$, and $-1$, we obtain the spherical, planar, and hyperbolic spacetimes…

General Relativity and Quantum Cosmology · Physics 2019-01-11 Kai Lin , Fei-Hung Ho , Wei-Liang Qian

We describe an action principle, within the framework of the Eddington gravity, which incorporates the matter fields in a simple manner. Interestingly, the gravitational field equations derived from this action is identical to the…

General Relativity and Quantum Cosmology · Physics 2021-03-24 Sumanta Chakraborty , T. Padmanabhan

The discrepancy between the observed value of the cosmological constant (CC) and its expected value from quantum field theoretical considerations motivates the search for a theory in which the CC is decoupled from the vacuum energy. In this…

General Relativity and Quantum Cosmology · Physics 2025-01-14 Justin C. Feng , Pisin Chen

We present a theory based upon the treatment of the gravitational field as a sea of gravity quanta, as defined elsewhere. The resultant model for the Universe is a static one, like Einstein first saw, with a new feature: a local shrinking…

General Physics · Physics 2015-06-26 Antonio Alfonso-Faus

The covariant canonical transformation theory applied to the relativistic Hamiltonian theory of classical matter fields in dynamical space-time yields a novel (first order) gauge field theory of gravitation. The emerging field equations…

General Relativity and Quantum Cosmology · Physics 2023-11-29 David Vasak , Johannes Kirsch , Dirk Kehm , Juergen Struckmeier

Unimodular gravity addresses the old cosmological constant (CC) problem, explaining why such constant is not at least as large as the largest particle mass scale, but classically it is indistinguishable from ordinary gravity. Conversely,…

High Energy Physics - Theory · Physics 2024-08-05 Alberto Salvio

A new gauge theory of gravity is presented. The theory is constructed in a flat background spacetime and employs gauge fields to ensure that all relations between physical quantities are independent of the positions and orientations of the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Anthony Lasenby , Chris Doran , Stephen Gull

Well tempering is one of the few classical field theory methods for solving the original cosmological constant problem, dynamically canceling a large (possibly Planck scale) vacuum energy and leaving the matter component intact, while…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-15 Stephen Appleby , Eric V. Linder

We show that it is possible to solve the cosmological constant (CC) problem in a discrete quantum gravity theory based on Regge calculus by using the effective action approach and a special path-integral measure. The effective cosmological…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Aleksandar Mikovic , Marko Vojinovic

The purpose of this article is twofold. First, by means of Padmanabhan's proposal on the emergence nature of gravity, we recover the $\Lambda$CDM model and the effect of the dark matter in the context of cosmology. Toward this goal, we use…

General Relativity and Quantum Cosmology · Physics 2025-05-06 Kimet Jusufi , Ahmad Sheykhi

We study the evolution of cosmological perturbations, using a hybrid approximation scheme which upgrades the weak-field limit of Einstein's field equations to account for post-Newtonian scalar and vector metric perturbations and for…

Astrophysics · Physics 2007-05-23 Carmelita Carbone , Sabino Matarrese