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Related papers: Quantum Gravity via Manifold Positivity

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A calculational scheme of quantum-gravitational effects on the physical quantities is proposed. The calculations are performed in 4-$\epsilon$ dimension with $1/N$-expansion scheme, where the Einstein gravity is renormalizable and it has an…

High Energy Physics - Theory · Physics 2009-10-22 Kazuo Ghoroku

We study dimensionally restricted non-perturbative causal set quantum dynamics in $2$ and $3$ spacetime dimensions with non-trivial global spatial topology. The causal set sample space is generated from causal embeddings into spacetime…

General Relativity and Quantum Cosmology · Physics 2020-04-08 William J. Cunningham , Sumati Surya

It is shown how one, guided by causality, starting from so-called dynamical triangulations, is led to a candidate of quantum gravity that describes our Universe. This theory is based on W- and Jordan algebras. It explains how our Universe…

General Relativity and Quantum Cosmology · Physics 2023-12-27 Yoshiyuki Watabiki

We propose that at the beginning of the universe gravity existed in a limbo either because it was switched off or because it was only conformally coupled to all particles. This picture can be reverse-engineered from the requirement that the…

General Relativity and Quantum Cosmology · Physics 2015-12-09 Giovanni Amelino-Camelia , Michele Arzano , Giulia Gubitosi , Joao Magueijo

Cosmic acceleration can be achieved not only with a sufficiently flat scalar field potential but through kinetic terms coupled to gravity. These derivative couplings impose a shift symmetry on the scalar field, aiding naturalness. We write…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-29 Giulia Gubitosi , Eric V. Linder

An earlier proposed theory with linear-gonihedhic action for quantum gravity is reviewed. One can consider this theory as a "square root" of classical gravity with a new fundamental constant of dimension one. We demonstrate also, that the…

High Energy Physics - Theory · Physics 2009-10-30 G. K. Savvidy

A positive semi-definite Euclidean action for arbitrary four-topologies can be constructed by adding appropriate Yang-Mills and topological terms to the Samuel-Jacobson-Smolin action of gravity with (anti)self-dual variables. Moreover,…

General Relativity and Quantum Cosmology · Physics 2011-07-19 Chopin Soo

Exactly soluble models can serve as excellent tools to explore conceptual issues in non-perturbative quantum gravity. In perturbative approaches, it is only the two radiative modes of the linearized gravitational field that are quantized.…

General Relativity and Quantum Cosmology · Physics 2022-11-04 Abhay Ashtekar

When four-dimensional general relativity is embedded in an unconstrained man-ner in a fifth dimension, the physical quantities of spacetime can be interpreted as geometrical properties related to the extra dimension. It has become…

General Relativity and Quantum Cosmology · Physics 2010-06-18 Paul S. Wesson

This paper is a serious attempt at reconciling quantum and classical mechanics through the concept of dynamic space and the acceptance of non-zero Ricci tensor for vacuum. Starting with scalar particles, the paper shows that with those two…

General Physics · Physics 2007-05-23 Jose B. Almeida

Twenty years ago, by extending the Wightman axiom framework, it has been found possible to quantize only a conformal factor of the gravitational field. Gravitons being excluded from this quantum scalar field theory, numerous attempts were…

General Relativity and Quantum Cosmology · Physics 2007-05-23 G. Burdet , M. Perrin

Quantum gravity places entirely new challenges on the formulation of a consistent theory as well as on an extraction of potentially observable effects. Quantum corrections due to the gravitational field are commonly expected to be tiny…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald

These Lecture Notes provide an elementary introduction to the quantization of two-dimensional quantum gravity. Nothing beyond undergratuate physics and mathematic is required. Explicit formulas for the partition functions for universes with…

High Energy Physics - Theory · Physics 2022-04-05 Jan Ambjorn

We study quantum gravity in $2+\epsilon$ dimensions in such a way to preserve the volume preserving diffeomorphism invariance. In such a formulation, we prove the following trinity: the general covariance, the conformal invariance and the…

High Energy Physics - Theory · Physics 2011-08-17 T. Aida , Y. Kitazawa , H. Kawai , M. Ninomiya

The current acceleration of the universe leads us to investigate higher dimensional gravity theory, which is able to explain acceleration from a theoretical view point without the need of introducing dark energy by hand. We argue that the…

General Relativity and Quantum Cosmology · Physics 2009-06-26 S. Chatterjee , D. Panigrahi

General relativity describes the gravitational field geometrically and in a self-interacting way because it couples to all forms of energy, including its own. Both features make finding a quantum theory difficult, yet it is important in the…

General Relativity and Quantum Cosmology · Physics 2011-09-02 Martin Bojowald

A classical dynamical system in a four-dimensional Euclidean space with universal time is considered. The space is hypothesized to be originally occupied by a uniform substance, pictured as a liquid, which at some time became supercooled.…

High Energy Physics - Theory · Physics 2013-06-19 Michael Grady

Each approach to the quantum-gravity problem originates from expertise in one or another area of theoretical physics. The particle-physics perspective encourages one to attempt to reproduce in quantum gravity as much as possible of the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Giovanni Amelino-Camelia

The Einstein-Hilbert action (and thus the dynamics of gravity) can be obtained by combining the principle of equivalence, special relativity and quantum theory in the Rindler frame and postulating that the horizon area must be proportional…

General Relativity and Quantum Cosmology · Physics 2009-11-07 T. Padmanabhan

Measurable quantities that have positive values in classical dynamical systems need not to be positive in quantum theory. For example, consider a free quantum mechanical particle in one dimension. There are quantum states in which the…

Quantum Physics · Physics 2017-12-12 Daniela Cadamuro