English
Related papers

Related papers: Conformal gravity and a natural solution to the co…

200 papers

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

We trace the origin of the cosmological constant problem to the assumption that Newton's constant $G$ sets the scale for cosmology. And then we show that once this assumption is relaxed, the very same cosmic acceleration which has served to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Philip D. Mannheim

A finite quantum gravity theory is used to resolve the cosmological constant problem. A fundamental quantum gravity scale, \Lambda_G \leq 10^{-3} eV, is introduced above which the quantum corrections to the vacuum energy density coupled to…

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

Recently, there have been claims in the literature that the cosmological constant problem can be dynamically solved by specific compactifications of gravity from higher-dimensional toy models. These models have the novel feature that in the…

High Energy Physics - Theory · Physics 2016-07-04 Mark P. Hertzberg , Ali Masoumi

The cosmological constant $\Lambda$ is a free parameter in Einstein's equations of gravity. We propose to fix its value with a boundary condition: test particles should be free when outside causal contact, e.g. at infinity. Under this…

General Physics · Physics 2019-05-24 Enrique Gaztanaga

After a short history of the $\Lambda$-term it is explained why the (effective) cosmological constant is expected to obtain contributions from short-distance physics, corresponding to an energy at least as large as the Fermi scale. The…

Astrophysics · Physics 2007-05-23 Norbert Straumann

We argue that, when a theory of gravity and matter is endowed with (classical) conformal symmetry, the fine tuning required to obtain the cosmological constant at its observed value can be significantly reduced. Once tuned, the cosmological…

General Relativity and Quantum Cosmology · Physics 2018-10-23 Stefano Lucat , Tomislav Prokopec , Bogumila Swiezewska

In the present article, which is the first part of a work in three parts, we build an equation of quantum gravity. This equation is tensorial, is equivalent to general relativity in vacuum, but differs completely from general relativity…

General Physics · Physics 2007-11-25 Christophe Real

We consider further consequences of recently [1] revealed role of cosmological constant \Lambda as of a physical constant, along with the gravitational one to define the gravity i.e. the General Relativity and its low-energy limit. We now…

General Physics · Physics 2019-03-13 V. G. Gurzadyan , A. Stepanian

Next year we will celebrate 100 years of the cosmological term, $\Lambda$, in Einstein's gravitational field equations, also 50 years since the cosmological constant problem was first formulated by Zeldovich, and almost about two decades of…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-14 Joan Sola

We have critically compared different approaches to the cosmological constant problem, which is at the edge of elementary particle physics and cosmology. This problem is deeply connected with the difficulties formulating a theory of quantum…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Stefan Nobbenhuis

The current standard cosmological model is constructed within the framework of general relativity with a cosmological constant $\Lambda$, which is often associated with dark energy, and phenomenologically explains the accelerated cosmic…

General Relativity and Quantum Cosmology · Physics 2023-06-27 Jiamin Hou , Julian Bautista , Maria Berti , Carolina Cuesta-Lazaro , César Hernández-Aguayo , Tilman Tröster , Jinglan Zheng

Observations indicate that our universe is characterized by a late-time accelerating phase, possibly driven by a cosmological constant $\Lambda$, with the dimensionless parameter $\Lambda L_P^2 \simeq 10^{-122}$, where $L_P = (G \hbar…

General Relativity and Quantum Cosmology · Physics 2014-06-04 T. Padmanabhan , Hamsa Padmanabhan

We investigate the gravitational property of the quantum vacuum by treating its large energy density predicted by quantum field theory seriously and assuming that it does gravitate to obey the equivalence principle of general relativity. We…

General Relativity and Quantum Cosmology · Physics 2019-04-22 Qingdi Wang , Zhen Zhu , William G. Unruh

The flatness and cosmological constant problems are solved with varying speed of light c, gravitational coupling strength G and cosmological parameter Lambda, by explicitly assuming energy conservation of observed matter. The present…

General Relativity and Quantum Cosmology · Physics 2009-10-31 P. Gopakumar , G. V. Vijayagovindan

I propose an observationally and theoretically consistent resolution of the cosmological constant problem: $\Lambda$ is a counterterm -- with a running coupling -- that balances the monopole celestial sky average of the kinetic energy of…

General Relativity and Quantum Cosmology · Physics 2024-04-03 David L. Wiltshire

The cosmological constant problem is one of the greatest challenges in contemporary physics, since it is deeply rooted in the problematic interplay between quantum fields and gravity. The aim of this work is to review the key conceptual…

General Relativity and Quantum Cosmology · Physics 2025-04-23 Federico Scali

A finite and unitary nonlocal formulation of quantum gravity is applied to the cosmological constant problem. The entire functions in momentum space at the graviton-standard model particle loop vertices generate an exponential suppression…

General Relativity and Quantum Cosmology · Physics 2016-02-08 J. W. Moffat

We explore the possibility of a consistent cosmology based on the gauge-fixing independent running of the gravitational and cosmological constants ($G$ and $\Lambda$) in the framework of effective quantum gravity. In particular, their…

General Relativity and Quantum Cosmology · Physics 2024-04-30 Nicolas R. Bertini , Davi C. Rodrigues , Ilya L. Shapiro

The cosmological constant problem and the compatibility of gravity with quantum mechanics are the two most pressing problems in all of gravitational theory. While string theory nicely addresses the latter, it has so far failed to provide…

High Energy Physics - Theory · Physics 2007-07-17 Philip D. Mannheim
‹ Prev 1 2 3 10 Next ›