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A fully consistent linear perturbation theory for cosmology is derived in the presence of quantum corrections as they are suggested by properties of inverse volume operators in loop quantum gravity. The underlying constraints present a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald , Golam Mortuza Hossain , Mikhail Kagan , S. Shankaranarayanan

We study the quantum-gravitational corrections to the power spectrum of a gauge-invariant inflationary scalar perturbations in a closed model of a universe. We consider canonical quantum gravity as an approach to quantizing gravity. This…

General Relativity and Quantum Cosmology · Physics 2023-02-15 Tatevik Vardanyan , Claus Kiefer

I describe the treatment of gravity as a quantum effective field theory. This allows a natural separation of the (known) low energy quantum effects from the (unknown) high energy contributions. Within this framework, gravity is a well…

General Relativity and Quantum Cosmology · Physics 2010-11-01 John F. Donoghue

Multi-messenger astronomy provides us with the possibility of discovering phenomenological signatures of quantum-gravity effects. This should be of paramount importance in the pursuit of an elusive quantum theory for the gravitational…

General Relativity and Quantum Cosmology · Physics 2023-12-25 Gabriel Menezes

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 compute the one-loop quantum corrections to the gravitational potentials of a spinning point particle in a de Sitter background, due to the vacuum polarisation induced by conformal fields in an effective field theory approach. We…

High Energy Physics - Theory · Physics 2017-04-19 Markus B. Fröb , Enric Verdaguer

The present paper is the companion of [1] in which we proposed a scheme that tries to derive the Quantum Field Theory (QFT) on Curved Spacetimes (CST) limit from background independent Quantum General Relativity (QGR). The constructions of…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Hanno Sahlmann , Thomas Thiemann

Perturbative quantum gravity formalism is applied to compute the lowest order corrections to the classical spatially flat cosmological FLRW solution (for the radiation). The presented approach is analogous to the approach applied to compute…

General Relativity and Quantum Cosmology · Physics 2011-03-23 Bogusław Broda

The consistent embedding of Loop Quantum Gravity (LQG) effects within the Standard Model requires a rigorous understanding of how Planck-scale deformations manifest at low energies. While phenomenological approaches often introduce…

General Physics · Physics 2026-03-03 Leonardo P. G. De Assis

We consider scattering in quantum gravity and derive long-range classical and quantum contributions to the scattering of light-like bosons and fermions (spin-0, spin-1/2, spin-1) from an external massive scalar field, such as the Sun or a…

High Energy Physics - Theory · Physics 2017-04-07 N. E. J. Bjerrum-Bohr , John F. Donoghue , Barry R. Holstein , Ludovic Plante , Pierre Vanhove

Within a perturbative cosmological regime of loop quantum gravity corrections to effective constraints are computed. This takes into account all inhomogeneous degrees of freedom relevant for scalar metric modes around flat space and results…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald , Hector Hernandez , Mikhail Kagan , Aureliano Skirzewski

In this paper we compute the spin-dependent terms of the gravitational potential for general spinning bodies at the leading Newton's constant $G$ and to all orders in spin. We utilize the on-shell approach, which extracts the classical…

High Energy Physics - Theory · Physics 2020-09-29 Ming-Zhi Chung , Yu-tin Huang , Jung-Wook Kim

Loop quantum gravity in its Hamiltonian form relies on a connection formulation of the gravitational phase space with three key properties: 1.) a compact gauge group, 2.) real variables, and 3.) canonical Poisson brackets. In conjunction,…

General Relativity and Quantum Cosmology · Physics 2024-12-09 Norbert Bodendorfer , Konstantin Eder , Xiangdong Zhang

We present a systematic study of the cosmological dynamics resulting from an effective Hamiltonian, recently derived in loop quantum gravity using Thiemann's regularization and earlier obtained in loop quantum cosmology (LQC) by keeping the…

General Relativity and Quantum Cosmology · Physics 2018-04-25 Bao-Fei Li , Parampreet Singh , Anzhong Wang

The Kawai-Lewellen-Tye (KLT) relations derived from string theory tell us that perturbative gravity amplitudes are the "square" of the corresponding amplitudes in gauge theory. Starting from the light-cone Lagrangian for pure gravity we…

High Energy Physics - Theory · Physics 2008-11-26 Sudarshan Ananth , Stefan Theisen

Using Wilsonian procedure (renormalization group improvement) we discuss the finite quantum corrections to black hole entropy in renormalizable theories. In this way, the Wilsonian black hole entropy is found for GUTs (of asymptotically…

General Relativity and Quantum Cosmology · Physics 2009-09-17 Sergei D. Odintsov , Yongsung Yoon

Effective equations are often useful to extract physical information from quantum theories without having to face all technical and conceptual difficulties. One can then describe aspects of the quantum system by equations of classical type,…

High Energy Physics - Theory · Physics 2008-11-26 Martin Bojowald , Aureliano Skirzewski

We perform the canonical quantization of a general scalar-tensor theory and derive the first quantum gravitational corrections following from a semi-classical expansion of the Wheeler-DeWitt equation. The non-minimal coupling of the scalar…

General Relativity and Quantum Cosmology · Physics 2018-07-12 Christian F. Steinwachs , Matthijs L. van der Wild

A new representation of Quantum Gravity is developed. This formulation is based on an extension of the group of loops. The enlarged group, that we call the Extended Loop Group, behaves locally as an infinite dimensional Lie group. Quantum…

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

We argue that finite-region observables in quantum gravity are best approached in terms of boundary data on null hypersurfaces. This has far-reaching effects on the basic notions of classical and quantum mechanics, such as Hamiltonians and…

High Energy Physics - Theory · Physics 2013-09-23 Yasha Neiman