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Related papers: Loop quantum $f(R)$ theories

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We construct an operator that measures the length of a curve in four-dimensional Lorentzian vacuum quantum gravity. We work in a representation in which a $SU(2)$ connection is diagonal and it is therefore surprising that the operator…

General Relativity and Quantum Cosmology · Physics 2009-10-28 T. Thiemann

Yes, there is. - A new kind of gauge theory is introduced, where the minimal coupling and corresponding covariant derivatives are defined in the space of functions pertaining to the functional Schroedinger picture of a given field theory.…

Quantum Physics · Physics 2008-11-26 Hans-Thomas Elze

We study two--loop renormalization in $(2+\epsilon)$--dimensional quantum gravity. As a first step towards the full calculation, we concentrate on the divergences which are proportional to the number of matter fields. We calculate the…

High Energy Physics - Theory · Physics 2016-09-06 Toshiaki Aida , Yoshihisa Kitazawa , Jun Nishimura , Asato Tsuchiya

Recent work on the loop representation of quantum gravity has revealed previously unsuspected connections between knot theory and quantum gravity, or more generally, 3-dimensional topology and 4-dimensional generally covariant physics. We…

General Relativity and Quantum Cosmology · Physics 2007-05-23 John Baez

Loop Quantum Gravity is a nonperturbative and background independent program for the quantization of General Relativity. Its underlying formalism has been applied successfully to the study of cosmological spacetimes, both to test the…

General Relativity and Quantum Cosmology · Physics 2021-09-13 Beatriz Elizaga Navascués , Guillermo A. Mena Marugán

I describe a possible perspective on the current state of loop quantum gravity, at the light of the developments of the last years. I point out that a theory is now available, having a well-defined background-independent kinematics and a…

General Relativity and Quantum Cosmology · Physics 2011-05-25 Carlo Rovelli

A correlational dialect is introduced within the quantum theory language to give a unified treatment of finite-dimensional informational/operational quantum theories, infinite-dimensional relativistic quantum theories, and quantum gravity.…

Quantum Physics · Physics 2021-02-03 Ding Jia

The loop representation of quantum gravity has many formal resemblances to a background-free string theory. In fact, its origins lie in attempts to treat the string theory of hadrons as an approximation to QCD, in which the strings…

High Energy Physics - Theory · Physics 2007-05-23 John C. Baez

We propose a new representation for gauge theories and quantum gravity. It can be viewed as a generalization of the loop representation. We make use of a recently introduced extension of the group of loops into a Lie Group. This extension…

General Relativity and Quantum Cosmology · Physics 2009-10-22 C. Di Bartolo , R. Gambini , J. Griego , J. Pullin

The scheme of using the Chern-Simons action to regularize the gravitational Hamiltonian constraint is extended to including the Lorentzian term in the $k=0$ cosmological model. The Euclidean term and the Lorenzian term are thus regularized…

General Relativity and Quantum Cosmology · Physics 2020-10-12 Jinsong Yang , Cong Zhang , Yongge Ma

Since there are quantization ambiguities in constructing the Hamiltonian constraint operator in isotropic loop quantum cosmology, it is crucial to check whether the key features of loop quantum cosmology, such as the quantum bounce and…

General Relativity and Quantum Cosmology · Physics 2009-04-28 Jinsong Yang , You Ding , Yongge Ma

In any attempt to build a quantum theory of gravity, a central issue is to unravel the structure of space-time at the smallest scale. Of particular relevance is the possible definition of coordinate functions within the theory and the study…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alejandro Corichi , Jose A. Zapata

We derive the pure spin connection and constraint-free BF formulations of real four-dimensional Lorentzian vacuum General Relativity. In contrast to the existing complex formulations, an important advantage is that they do not require the…

General Relativity and Quantum Cosmology · Physics 2019-02-01 Ermis Mitsou

We discuss a new approach to the problem of quantum gravity in which the quantum mechanical structures that are traditionally fixed, such as the Fubini-Study metric in the Hilbert space of states, become dynamical and so implement the idea…

General Relativity and Quantum Cosmology · Physics 2022-11-28 Per Berglund , Tristan Hübsch , David Mattingly , Djordje Minic

In the canonical approach of loop quantum gravity, arguably the most important outstanding problem is finding and interpreting solutions to the Hamiltonian constraint. In this work, we demonstrate that methods of machine learning are in…

General Relativity and Quantum Cosmology · Physics 2024-10-18 Hanno Sahlmann , Waleed Sherif

A four dimensional generally covariant field theory is presented which describes non-dynamical three geometries coupled to scalar fields. The theory has an infinite number of physical observables (or constants of the motion) which are…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Viqar Husain

The main principle of affine quantum gravity is the strict positivity of the matrix \{\hat g_{ab}(x)\} composed of the spatial components of the local metric operator. Canonical commutation relations are incompatible with this principle,…

General Relativity and Quantum Cosmology · Physics 2010-03-15 John R. Klauder

We advance here a new gravity quantization procedure that explicitly utilizes York's analysis of the geometrodynamic degrees of freedom. This geometrodynamic procedure of quantization is based on a separation of the true dynamic variables…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Arkady Kheyfets , Warner A. Miller

Within the general framework of $f(R)$ gravity, we introduce a function of the electromagnetic curvature invariant $f(\mathbb{F})$ that couples minimally to gravitation to ensure a consistent treatment of curvature functions in these…

General Relativity and Quantum Cosmology · Physics 2026-03-19 Francesco Bajardi , Micol Benetti , Salvatore Capozziello , Abedennour Dib

General Theory of Relativity and Quantum theory gives two different description of the same mother nature in the big and small scale respectively. Mathematical languages of these two theories are entirely different, one is geometric while…

General Physics · Physics 2020-05-11 Sijo K. Joseph