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Related papers: Instantons in the Quantum Framework of 2D Gravity

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The semiclassical gravity describes gravitational back-reactions of the classical spacetime interacting with quantum matter fields but the quantum effects on the background is formally defined as higher derivative curvatures. These induce…

General Relativity and Quantum Cosmology · Physics 2020-02-06 Hiroki Matsui , Naoki Watamura

We study ultra-Planckian $2\to2$ scattering in an Abelian gauge theory coupled to agravity, the scale-free and renormalizable realization of quadratic quantum gravity. Focusing on charged fermions and scalars interacting with the photon and…

High Energy Physics - Theory · Physics 2026-04-06 I. F. Cunha , A. C. Lehum

This paper explores the theoretical implications of quantum gravity by analyzing compact stellar objects, presenting three distinct models that serve as alternatives to traditional black holes. These models are characterized by their…

General Relativity and Quantum Cosmology · Physics 2025-12-02 Salvatore Samuele Sirletti , Piero Nicolini , Mariafelicia De Laurentis

A new formulation of relativistic quantum mechanics is proposed in the framework of the rest-frame instant form of dynamics with its instantaneous Wigner 3-spaces and with its description of the particle world-lines by means of derived…

High Energy Physics - Theory · Physics 2015-05-13 David Alba , Horace Crater , Luca Lusanna

The scaling properties of quantum gravity are discussed by employing a class of proper-time regulators in the functional flow equation for the conformal factor within the formalism of the background field method. Renormalization group…

High Energy Physics - Theory · Physics 2013-12-10 Alfio Bonanno , Filippo Guarnieri

We study a system of two pointlike particles coupled to three dimensional Einstein gravity. The reduced phase space can be considered as a deformed version of the phase space of two special-relativistic point particles in the centre of mass…

General Relativity and Quantum Cosmology · Physics 2010-05-28 Jorma Louko , Hans-Juergen Matschull

We outline, test, and apply a new scheme for nonpertubative analyses of quantized field systems in contact with dynamical gravity. While gravity is treated classically in the present paper, the approach lends itself for a generalization to…

General Relativity and Quantum Cosmology · Physics 2020-12-30 Maximilian Becker , Martin Reuter

It is proposed that a complete understanding of two-dimensional quantum gravity and its emergence in random matrix models requires fully embracing {\it both} Wigner (statistics) and 't Hooft (geometry). Using non-perturbative definitions of…

High Energy Physics - Theory · Physics 2022-03-22 Clifford V. Johnson

The influence of nonperturbative fields on instantons in quantum chromodynamics is studied. Effective action for instanton is derived in bilocal approximation and it is demonstrated that stochastic background gluon fields are responsible…

High Energy Physics - Phenomenology · Physics 2007-05-23 N. O. Agasian , S. M. Fedorov

The microscopic theories of quantum gravity related to integrable lattice models can be constructed as special deformations of pure gravity. Each such deformation is defined by a second order differential operator acting on the coupling…

High Energy Physics - Theory · Physics 2007-05-23 I. K. Kostov

We consider a simplified model of quantum gravity using a mini-superspace description of an isotropic and homogeneous universe with dust. We derive the corresponding Friedmann equations for the scale factor, which now contain a dependence…

General Relativity and Quantum Cosmology · Physics 2020-04-03 Thibaut Demaerel , Christian Maes , Ward Struyve

We consider 4D quantum-dilaton gravity with the most general coupling in a homogeneous and isotropic universe, especially an inflationary one, which is essentially characterized by an exponentially expanding scale factor with time. We show…

High Energy Physics - Theory · Physics 2009-10-30 Hiroyuki Takata

We study quantum fluctuations in the lightcone metric of the 4-d Einstein-Hilbert action via dimensional reduction to Jackiw-Teitelboim (JT) gravity. In particular, we show that, in Einstein gravity, the causal development of a region in…

High Energy Physics - Theory · Physics 2023-01-16 Sergei Gukov , Vincent S. H. Lee , Kathryn M. Zurek

Well defined quantum field theory (QFT) for the electroweak force including quantum electrodynamics (QED) and the weak force is obtained by considering natural unitary representations of a group $K\subset U(2,2)$, where $K$ is locally…

Mathematical Physics · Physics 2021-06-16 John Mashford

We discuss non-perturbative effects in the ABJM model due to monopole instantons. We begin by constructing the instanton solutions in the $U(2)\times U(2)$ model, explicitly, and computing the Euclidean action. The Wick-rotated Lagrangian…

High Energy Physics - Theory · Physics 2011-06-02 Kazuo Hosomichi , Ki-Myeong Lee , Sangmin Lee , Sungjay Lee , Jaemo Park , Piljin Yi

In the framework of the two-form gravity, which is classically equivalent to the Einstein gravity, the one-loop effective potential for the conformal factor of metric is calculated in the finite volume and in the finite temperature by…

High Energy Physics - Theory · Physics 2015-06-26 Miyuki KATSUKI , Shin'ichi NOJIRI , Akio SUGAMOTO

In this paper we carry out a quantization of gravity coupled to massless spin 1/2 fermions through the instanton representation of Plebanski gravity. We have constructed a Hilbert space of states for this model, and we have computed the…

General Relativity and Quantum Cosmology · Physics 2010-07-13 Eyo Eyo Ita

We model A_k and D_k asymptotically locally flat gravitational instantons on the moduli spaces of solutions of U(2) Bogomolny equations with prescribed singularities. We study these moduli spaces using Ward correspondence and find their…

High Energy Physics - Theory · Physics 2009-10-31 S. A. Cherkis , A. Kapustin

The quantum cosmology of two-dimensional dilaton-gravity models is investigated. A class of models is mapped onto the constrained oscillator-ghost-oscillator model. A number of exact and approximate solutions to the corresponding…

General Relativity and Quantum Cosmology · Physics 2008-11-26 James E. Lidsey

We study canonical quantization of a class of 2d dilaton gravity models, which contains the model proposed by Callan, Giddings, Harvey and Strominger. A set of non-canonical phase space variables is found, forming an $SL(2,{\bf R}) \times…

High Energy Physics - Theory · Physics 2009-01-16 A. Mikovic