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Related papers: Quantum Corrections to Unimodular Gravity

200 papers

Quantum gravitational effects in black hole spacetimes with a cosmological constant $\Lambda$ are considered. The effective quantum spacetimes for the black holes are constructed by taking into account the renormalization group improvement…

General Relativity and Quantum Cosmology · Physics 2017-06-14 Ramon Torres

We show that the cosmological constant appears as a Lagrange multiplier if nature is described by a canonical noncommutative spacetime. It is thus an arbitrary parameter unrelated to the action and thus to vacuum fluctuations. The…

High Energy Physics - Theory · Physics 2008-11-26 Xavier Calmet

Unimodular gravity is an interesting approach to address the cosmological constant problem, since the vacuum energy density of quantum fields does not gravitate in this framework, and the cosmological constant appears as an integration…

General Relativity and Quantum Cosmology · Physics 2018-04-11 Yuri Bonder , Cristobal Corral

Recently, a new framework for describing the multiverse has been proposed which is based on the principles of quantum mechanics. The framework allows for well-defined predictions, both regarding global properties of the universe and…

High Energy Physics - Theory · Physics 2013-05-29 Grant Larsen , Yasunori Nomura , H. L. L. Roberts

In the investigation and resolution of the cosmological constant problem the inclusion of the dynamics of quantum gravity can be a crucial step. In this work we suggest that the quantum constraints in a canonical theory of gravity can…

High Energy Physics - Theory · Physics 2013-04-23 Jan Govaerts , Simone Zonetti

We consider a dynamical approach to the cosmological constant. There is a scalar field with a potential whose minimum occurs at a generic, but negative, value for the vacuum energy, and it has a non-standard kinetic term whose coefficient…

High Energy Physics - Theory · Physics 2016-09-06 Shinji Mukohyama , Lisa Randall

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 a model of gravity and matter fields which is invariant only under unimodular general coordinate transformations (GCT). The determinant of the metric is treated as a separate field which transforms as a scalar under unimodular…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-04 Pankaj Jain , Atul Jaiswal , Purnendu Karmakar , Gopal Kashyap , Naveen K. Singh

We introduce new techniques that can preserve unitarity of the system including ghost particles. Negative norms of the particles can be involved in zero-norm states by constraints of the physical space. These are useful to apply the…

General Relativity and Quantum Cosmology · Physics 2010-10-26 Hajime Isimori

ElectroMagnetic Quantum Gravity (EMQG) is applied to the problem of the Cosmological Constant. EMQG is a quantum gravity theory (ref. 1) in which the virtual particles of the quantum vacuum play a very important role in all gravitational…

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

The bare bones of a theory of quantum gravity are exposed. It may have the potential to solve the cosmological constant problem. Less certain is its behavior in the Newtonian limit.

High Energy Physics - Theory · Physics 2007-05-23 Paul Federbush

In linearized quantum gravity, a shift of the average energy-momentum can be compensated by a shift of the average gravitational field. This allows a renormalization scheme that naturally removes the contribution of quantum vacuum…

General Relativity and Quantum Cosmology · Physics 2007-08-28 H. Nikolic

With attempts to quench the cosmological constant $\Lambda$ having so far failed, we instead investigate what could be done if $\Lambda$ is not quenched and actually gets to be as big as elementary particle physics suggests. Since the…

Astrophysics · Physics 2007-05-23 Philip D. Mannheim

We present a solution to the cosmological constant, the zero-point energy, and the quantum gravity problems within a single comprehensive framework. We show that in quantum theories of gravity in which the zero-point energy density of the…

High Energy Physics - Theory · Physics 2011-02-23 Philip D. Mannheim

We compute the cosmological constant in a scale invariant scalar field theory. The gravitational action is also suitably modified to respect scale invariance. Due to scale invariance the theory does not admit a cosmological constant term.…

High Energy Physics - Phenomenology · Physics 2010-11-15 Pankaj Jain , Subhadip Mitra

The infinite dimensional generalization of the quantum mechanics of extended objects, namely, the quantum field theory of extended objects is employed to address the hitherto nonrenormalizable gravitational interaction following which the…

High Energy Physics - Theory · Physics 2009-09-25 Ramchander R. Sastry

We show how to reliably calculate quantum gravitational corrections to cosmological models using the unique effective action formalism for quantum gravity. Our calculations are model independent and apply to any ultra-violet complete theory…

High Energy Physics - Theory · Physics 2025-01-07 Xavier Calmet , Roberto Casadio , Marco Sebastianutti

A key incentive of quantum gravity is the removal of spacetime singularities plaguing the classical theory. We compute the non-perturbative momentum-dependence of a specific structure function within the gravitational asymptotic safety…

High Energy Physics - Theory · Physics 2019-09-11 Lando Bosma , Benjamin Knorr , Frank Saueressig

We examine the general issue of whether a scale dependent cosmological constant can be consistent with general covariance, a problem that arises naturally in the treatment of quantum gravitation where coupling constants generally run as a…

High Energy Physics - Theory · Physics 2015-06-12 Herbert W. Hamber , Reiko Toriumi

We study unimodular gravity in the context of cosmology, particularly some interesting consequences that might be able to describe the background cosmology and the late cosmic acceleration. We focus our attention on the hypothesis of…

General Relativity and Quantum Cosmology · Physics 2019-06-26 Miguel A. García-Aspeitia , C. Martínez-Robles , A. Hernández-Almada , Juan Magaña , V. Motta