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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

Bootstrapped Newtonian gravity was developed with the purpose of estimating the impact of quantum physics in the nonlinear regime of the gravitational interaction, akin to corpuscular models of black holes and inflation. In this work, we…

General Relativity and Quantum Cosmology · Physics 2021-02-22 Roberto Casadio , Andrea Giusti

The anomalous dimensions of the Planck mass and the cosmological constant are calculated in a renormalizable quantum conformal gravity with a single dimensionless coupling, which is formulated using dimensional regularization on the basis…

High Energy Physics - Theory · Physics 2016-04-11 Ken-ji Hamada , Mikoto Matsuda

For purposes of quantization, classical gravity is normally expressed by canonical variables, namely the metric $g_{ab}(x)$ and the momentum $\pi^{cd}(x)$. Canonical quantization requires a proper promotion of these classical variables to…

General Relativity and Quantum Cosmology · Physics 2020-04-22 John R. Klauder

Based on the assertion that the cosmological constant problem is essentially a quantum gravity problem, the framework which addresses the cosmological constant problem should also bear a picture for the ``quantum space-time''. In this talk…

High Energy Physics - Phenomenology · Physics 2009-10-07 M. M. Sheikh-Jabbari

For a 1+1 dimensional theory of gravity with torsion different approaches to the formulation of a quantum theory are presented. They are shown to lead to the same finite dimensional quantum system. Conceptual questions of quantum gravity…

High Energy Physics - Theory · Physics 2010-04-06 Peter Schaller , Thomas Strobl

We present a brief description of the ``consistent discretization'' approach to classical and quantum general relativity. We exhibit a classical simple example to illustrate the approach and summarize current classical and quantum…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Rodolfo Gambini , Jorge Pullin

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

Heisenberg's nonperturbative quantization technique is applied to the nonpertrubative quantization of gravity. An infinite set of equations for all Green's functions is obtained. An approximation is considered where: (a) the metric remains…

General Relativity and Quantum Cosmology · Physics 2014-11-07 Vladimir Dzhunushaliev

In the framework of the recently proposed models of massive gravity, defined with respect to a de Sitter reference metric, we obtain new homogeneous and isotropic solutions for arbitrary cosmological matter and arbitrary spatial curvature.…

High Energy Physics - Theory · Physics 2015-06-05 David Langlois , Atsushi Naruko

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

The existence of a small, non-zero cosmological constant is one of the major puzzles in fundamental physics. Naively, quantum field theory arguments would imply a cosmological constant which is up to 10$^{120}$ times larger than the…

General Physics · Physics 2022-09-08 Michael Bishop , Joey Contreras , Peter Martin , Douglas Singleton

A "quantum-first" approach to gravity is described, where rather than quantizing general relativity, one seeks to formulate the physics of gravity within a quantum-mechanical framework with suitably general postulates. Important guides are…

High Energy Physics - Theory · Physics 2018-05-23 Steven B. Giddings

This article summarizes a new approach to quantum gravity based on the concepts of modular spacetime, Born geometry, and metastring theory and their applications to quantum gravity phenomenology. In particular, we discuss a new…

General Relativity and Quantum Cosmology · Physics 2021-09-28 Douglas Edmonds , Djordje Minic , Tatsu Takeuchi

We study the quantum cosmology of a flat Friedmann-Lema\^{i}tre-Robertson-Walker universe filled with a (free) massless scalar field and a perfect fluid that represents radiation or a cosmological constant whose value is not fixed by the…

General Relativity and Quantum Cosmology · Physics 2020-10-01 Steffen Gielen , Lucía Menéndez-Pidal

We study the derivation of the effective equation of motion for a pointlike particle in the framework of quantum gravity. Just like the geodesic motion of a classical particle is a consequence of classical field theory coupled to general…

General Relativity and Quantum Cosmology · Physics 2019-10-01 Francisco Pipa , Nikola Paunkovic , Marko Vojinovic

The cosmological constant problem is the principal obstacle in the attempt to interpret dark energy as the quantum vacuum energy. We suggest that the obstacle can be removed, i.e. that the cosmological constant problem can be resolved by…

General Physics · Physics 2012-01-24 Dragan Slavkov Hajdukovic

We recall a classical theory of torsion gravity with an asymmetric metric, sourced by a Nambu-Goto + Kalb-Ramond string . We explain why this is a significant gravitational theory, and in what sense classical general relativity is an…

General Relativity and Quantum Cosmology · Physics 2019-07-01 Tejinder P. Singh

One of the leading issues in quantum field theory and cosmology is the mismatch between the observed and calculated values for the cosmological constant in Einstein's field equations of up to 120 orders of magnitude. In this paper, we…

General Relativity and Quantum Cosmology · Physics 2023-09-21 Michael Bishop , Peter Martin , Douglas Singleton

We study FLRW cosmology, taking into account quantum gravitational corrections in the formalism of the exact renormalization group flow of the effective action for gravity. We calculate the quantum corrected scale factor, energy density,…

General Relativity and Quantum Cosmology · Physics 2022-10-26 Rituparna Mandal , Sunandan Gangopadhyay , Amitabha Lahiri