English
Related papers

Related papers: The Cosmological Constant Problem and Nonlocal Qua…

200 papers

One of the major issues confronting theoretical physics is finding a quantum theory of gravity and a resolution to the cosmological constant problem. It is believed that a true quantum theory of gravity will lead to a solution to the this…

High Energy Physics - Theory · Physics 2007-09-05 Edward Tetteh-Lartey

In this report, we discuss a candidate mechanism through which one might address the various cosmological constant problems. We first observe that the renormalization of gravitational couplings (induced by integrating out various matter…

High Energy Physics - Theory · Physics 2010-03-17 Subodh P. Patil

The cosmological constant problem is usually considered an inevitable feature of any effective theory capturing well-tested gravitational and matter physics, without regard to the details of short-distance gravitational couplings. In this…

High Energy Physics - Theory · Physics 2009-09-15 Raman Sundrum

We highlight the fact that the lack of scale invariance in the gravitational field equations of General Relativity results from the underlying assumption that the appropriate scale for the gravitational force should be linked to the atomic…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Robin Booth

Recently a scale invariant theory of gravity was constructed by imposing a conformal symmetry on general relativity. The imposition of this symmetry changed the configuration space from superspace - the space of all Riemannian 3-metrics…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Bryan Kelleher

We investigate the problem of metric fluctuations in the presence of the vacuum fluctuations of matter fields and critically assess the usual assertion that vacuum energy implies a Planckian cosmological constant. A new stochastic classical…

General Relativity and Quantum Cosmology · Physics 2008-06-19 Charles H. -T. Wang , Paolo M. Bonifacio , Robert Bingham , J. Tito Mendonca

Physics invites the idea that space contains energy whose gravitational effect approximates that of Einstein's cosmological constant, Lambda; nowadays the concept is termed dark energy or quintessence. Physics also suggests the dark energy…

Astrophysics · Physics 2008-11-26 P. J. E. Peebles , Bharat Ratra

We consider a model for gravity that is invariant under global scale transformations. It includes one extra real scalar field coupled non-minimally to the gravity fields. In this model all the dimensionful parameters like the gravitational…

General Relativity and Quantum Cosmology · Physics 2012-02-06 Pankaj Jain , Purnendu Karmakar , Subhadip Mitra , Sukanta Panda , Naveen K. Singh

We study the influence of the fluctuations of a Lorentz invariant and conserved vacuum on cosmological metric perturbations, and show that they generically blow up in the IR. We compute this effect using the K\"all\'en-Lehmann spectral…

High Energy Physics - Theory · Physics 2016-07-06 Niayesh Afshordi , Elliot Nelson

We extend General Relativity by promoting Planck scale and the cosmological constant into integration constants, interpreted as fluxes of $4$-forms hiding in the theory. When we include the charges of the $4$-forms, these `constants' can…

High Energy Physics - Theory · Physics 2022-10-05 Nemanja Kaloper

A framework for quantum field theory coupled to three-dimensional quantum gravity is proposed. The coupling with quantum gravity regulates the Feynman diagrams. One recovers the usual Feynman amplitudes in the limit as the cosmological…

General Relativity and Quantum Cosmology · Physics 2009-11-11 John W. Barrett

A modified-gravity-type model of two hypothetical massless vector fields is presented. These vector fields are gravitationally coupled to standard matter and an effective cosmological constant. Considered in a cosmological context, the…

High Energy Physics - Theory · Physics 2012-05-10 V. Emelyanov , F. R. Klinkhamer

The Cosmological Constant Problem emerges when Quantum Field Theory is applied to the gravitational theory, due to the enormous magnitude of the induced energy of the vacuum. The unique known solution of this problem involves an extremely…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Ilya L. Shapiro , Joan Sola

I review the lattice approach to quantum gravity, and how it relates to the non-trivial ultraviolet fixed point scenario of the continuum theory. After a brief introduction covering the general problem of ultraviolet divergences in gravity…

General Relativity and Quantum Cosmology · Physics 2009-04-17 Herbert W. Hamber

A mechanism to control the cosmological constant through a scalar field non-minimally coupled to gravity is proposed. By utilizing non-minimal phantom or quintessence, the cosmological constant, which may be large originally, can be…

High Energy Physics - Theory · Physics 2008-01-31 Je-an Gu

We briefly review the current status of a new quantum gravity theory called Electro-Magnetic Quantum Gravity. EMQG is manifestly compatible with Cellular Automata (CA) theory, and is based on a new theory of inertia proposed by R. Haisch,…

General Physics · Physics 2007-05-23 Tom Ostoma , Mike Trushyk

The paper deals with a modified theory of gravity and the cosmological consequences. Instead of concerning the field equations directly, we modify a conformally-related and equivalent equation, such that a spontaneous symmetry breaking at…

General Physics · Physics 2020-01-23 Christian Henke

A scalar-tensor theory of gravity is formulated in which $G$ and particle masses are allowed to vary. The theory yields a globally static cosmological model with no evolutionary timescales, no cosmological coincidences, and no flatness and…

General Physics · Physics 2015-10-01 Meir Shimon

We compare the recent loop quantum cosmology approach of Bojowald and co-workers with earlier quantum cosmological schemes. Because the weak-energy condition can now be violated at short distances, and not necessarily with a high energy…

General Relativity and Quantum Cosmology · Physics 2016-08-31 D. H. Coule

We present a general covariant action for massive gravity merging together a class of "non-polynomial" and super-renormalizable or finite theories of gravity with the non-local theory of gravity recently proposed by Jaccard, Maggiore and…

High Energy Physics - Theory · Physics 2013-11-08 Leonardo Modesto , Shinji Tsujikawa
‹ Prev 1 3 4 5 6 7 10 Next ›