scholarly journals Renormalizable and Unitary Lorentz Invariant Model of Quantum Gravity

2021 ◽  
Author(s):  
S. A. Larin
Keyword(s):  
General Relativity ◽  
Quantum Theory ◽  
Quantum Gravity ◽  
Curvature Tensor ◽  
Quantum Theory Of Gravitation ◽  
Proper Choice ◽  
Invariant Model ◽  
Self Consistent ◽  
Theory Of Gravitation

We analyze the R + R2 model of quantum gravity where terms quadratic in the curvature tensor are added to the General Relativity action. This model was recently proved to be a self-consistent quantum theory of gravitation, being both renormalizable and unitary. The model can be made practically indistinguishable from General Relativity at astrophysical and cosmological scales by the proper choice of parameters.

scholarly journals Renormalizable and Unitary Lorentz Invariant Model of Quantum Gravity

Universe ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 435
Author(s):  
Sergey A. Larin
Keyword(s):  
General Relativity ◽  
Quantum Theory ◽  
Quantum Gravity ◽  
Curvature Tensor ◽  
Quantum Theory Of Gravitation ◽  
Proper Choice ◽  
Invariant Model ◽  
Self Consistent ◽  
Theory Of Gravitation

We analyze the R+R2 model of quantum gravity where terms quadratic in the curvature tensor are added to the General Relativity action. This model was recently proved to be a self-consistent quantum theory of gravitation, being both renormalizable and unitary. The model can be made practically indistinguishable from General Relativity at astrophysical and cosmological scales by the proper choice of parameters.

scholarly journals Fourth-derivative relativistic quantum gravity

2018 ◽  
Vol 191 ◽  
pp. 07002 ◽  
Author(s):  
S.A. Larin
Keyword(s):  
Quantum Theory ◽  
Quantum Gravity ◽  
Curvature Tensor ◽  
Relativistic Quantum ◽  
Dimensional Regularization ◽  
Quantum Theory Of Gravitation ◽  
Graviton Propagator ◽  
Fourth Derivative ◽  
Theory Of Gravitation

We consider relativistic quantum gravity with the action including terms quadratic in the curvature tensor. This model is known to be renormalizable. We demonstrate that the model is also unitary. New expressions for the corresponding Lagrangian and the graviton propagator within dimensional regularization are derived. We argue that the considered model is the proper candidate for the fundamental quantum theory of gravitation.

scholarly journals Higher-derivative relativistic quantum gravity

2018 ◽  
Vol 33 (05) ◽  
pp. 1850028 ◽  
Author(s):  
S. A. Larin
Keyword(s):  
Quantum Theory ◽  
Quantum Gravity ◽  
Curvature Tensor ◽  
Relativistic Quantum ◽  
Dimensional Regularization ◽  
Quantum Theory Of Gravitation ◽  
Higher Derivative ◽  
Graviton Propagator ◽  
Theory Of Gravitation

Relativistic quantum gravity with the action including terms quadratic in the curvature tensor is analyzed. We derive new expressions for the corresponding Lagrangian and the graviton propagator within dimensional regularization. We argue that the considered model is a good candidate for the fundamental quantum theory of gravitation.

Black Holes and Quantum Gravity

2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Aurélien Barrau
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Theory ◽  
Quantum Gravity ◽  
Gravitational Waves ◽  
Quantum Theory Of Gravitation ◽  
Theoretical Physics ◽  
Radio Interferometry ◽  
Theory Of Gravitation ◽  
Observational Science

The search for a quantum theory of gravitation is considered one of the most important problems in theoretical physics. Might black holes provide a key? Researchers are beginning to think that the emergence of a true black hole astronomy based on the measurement of gravitational waves and radio interferometry could bring quantum gravity into the field of experimental or observational science.

scholarly journals Standard model and graviweak unification with (super)renormalizable gravity. Part I: Visible and invisible sectors of the universe

2015 ◽  
Vol 30 (09) ◽  
pp. 1550044 ◽  
Author(s):  
L. V. Laperashvili ◽  
H. B. Nielsen ◽  
A. Tureanu
Keyword(s):  
Standard Model ◽  
Quantum Gravity ◽  
Consistent Theory ◽  
Invariant Model ◽  
Higher Derivative ◽  
Self Consistent ◽  
Renormalizable Theory ◽  
Theory Of Gravity ◽  
Higgs Fields ◽  
The Universe

We develop a self-consistent Spin (4, 4)-invariant model of the unification of gravity with weak SU(2) gauge and Higgs fields in the visible and invisible sectors of our universe. We consider a general case of the graviweak unification, including the higher-derivative super-renormalizable theory of gravity, which is a unitary, asymptotically-free and perturbatively consistent theory of the quantum gravity.

“Prehistoric” Quantum Gravity

2020 ◽  
pp. 41-70
Author(s):  
Dean Rickles
Keyword(s):  
General Relativity ◽  
Quantum Theory ◽  
Gravitational Field ◽  
Quantum Gravity ◽  
Philosophical Nature

In this chapter we examine the very earliest work on the problem of quantum gravity (understood very liberally). We show that, even before the concept of the quantization of the gravitational field in 1929, there was a fairly lively investigation of the relationships between gravity and quantum stretching as far back as 1916, and certainly no suggestion that such a theory would not be forthcoming. Indeed, there are, rather, many suggestions explicitly advocating that an integration of quantum theory and general relativity (or gravitation, at least) is essential for future physics, in order to construct a satisfactory foundation. We also see how this belief was guided by a diverse family of underlying agendas and constraints, often of a highly philosophical nature.

scholarly journals Renormalizable and Unitary Model of Quantum Gravity

Symmetry ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1334
Author(s):  
S. A. Larin
Keyword(s):  
Quantum Theory ◽  
Quantum Gravity ◽  
Curvature Tensor ◽  
Relativistic Quantum ◽  
Dimensional Regularization ◽  
Graviton Propagator ◽  
Unitary Model ◽  
Theory Of Gravity ◽  
Made In

We consider R + R 2 relativistic quantum gravity with the action where all possible terms quadratic in the curvature tensor are added to the Einstein-Hilbert term. This model was shown to be renormalizable in the work by K.S. Stelle. In this paper, we demonstrate that the R + R 2 model is also unitary contrary to the statements made in the literature, in particular in the work by Stelle. New expressions for the R + R 2 Lagrangian within dimensional regularization and the graviton propagator are derived. We demonstrate that the R + R 2 model is a good candidate for the fundamental quantum theory of gravity.

scholarly journals The Quantum Cosmological Constant

Symmetry ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1130 ◽  
Author(s):  
Stephon Alexander ◽  
Joao Magueijo ◽  
Lee Smolin
Keyword(s):  
General Relativity ◽  
Quantum Theory ◽  
Quantum Gravity ◽  
Cosmological Constant ◽  
Uncertainty Relation ◽  
Time Variable ◽  
Transition Functions ◽  
New Interpretation ◽  
Chern Simons

We present an extension of general relativity in which the cosmological constant becomes dynamical and turns out to be conjugate to the Chern–Simons invariant of the Ashtekar connection on a spatial slicing. The latter has been proposed Soo and Smolin as a time variable for quantum gravity: the Chern–Simons time. In the quantum theory, the inverse cosmological constant and Chern–Simons time will then become conjugate operators. The “Kodama state” gets a new interpretation as a family of transition functions. These results imply an uncertainty relation between Λ and Chern–Simons time; the consequences of which will be discussed elsewhere.

scholarly journals On the emergence of the structure of physics

2018 ◽  
Vol 376 (2118) ◽  
pp. 20170231 ◽  
Author(s):  
S. Majid
Keyword(s):  
General Relativity ◽  
Quantum Theory ◽  
Quantum Gravity ◽  
Recent Work ◽  
Space Time ◽  
Quantum Space ◽  
Conceptual Level ◽  
Theme Issue ◽  
Self Duality ◽  
Born Reciprocity

We consider Hilbert’s problem of the axioms of physics at a qualitative or conceptual level. This is more pressing than ever as we seek to understand how both general relativity and quantum theory could emerge from some deeper theory of quantum gravity, and in this regard I have previously proposed a principle of self-duality or quantum Born reciprocity as a key structure. Here, I outline some of my recent work around the idea of quantum space–time as motivated by this non-standard philosophy, including a new toy model of gravity on a space–time consisting of four points forming a square. This article is part of the theme issue ‘Hilbert’s sixth problem’.

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