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Related papers: Fermion Doubling in Loop Quantum Gravity

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In this thesis we consider the problem of dynamics in canonical loop quantum gravity, primarily in the context of deparametrized models, in which a scalar field is taken as a physical time variable for the dynamics of the gravitational…

General Relativity and Quantum Cosmology · Physics 2021-01-01 Ilkka Mäkinen

We employ the Dirac-like equation for the gauge field proposed by Majorana to obtain an action that is symmetric under duality transformation. We also use the equivalence between duality and chiral symmetry in this fermion-like formulation…

High Energy Physics - Theory · Physics 2009-10-31 Everton M. C. Abreu , Marcelo Hott

The recently proposed loop representation, used previously to find exact solutions to the quantum constraints of general relativity, is here used to quantize linearized general relativity. The Fock space of graviton states and its…

High Energy Physics - Theory · Physics 2010-11-01 Abhay Ashtekar , Carlo Rovelli , Lee Smolin

An analytical approach for studying the cosmological scenario with a homogeneous tachyon field within the framework of loop quantum gravity is developed. Our study is based on the semi-classical regime where space time can be approximated…

General Relativity and Quantum Cosmology · Physics 2009-11-11 A. A. Sen

Nowadays, quantum simulation schemes come in two flavours. Either they are continuous-time discrete-space models (a.k.a Hamiltonian-based), pertaining to non-relativistic quantum mechanics. Or they are discrete-spacetime models (a.k.a…

Quantum Physics · Physics 2019-10-18 Giuseppe Di Molfetta , Pablo Arrighi

Recently in the framework of a two-loop order calculation for an effective field theory of scalar and vector fields interacting with the metric field we have shown that for the cosmological constant term which is fixed by the condition of…

High Energy Physics - Theory · Physics 2019-12-10 J. Gegelia , Ulf-G. Meißner

We investigate the interplay between confinement and the fermion doubling problem in Dirac-like Hamiltonians. Individually, both features are well known. First, simple electrostatic gates do not confine electrons due to the Klein tunneling.…

Mesoscale and Nanoscale Physics · Physics 2017-11-01 B. Messias de Resende , F. Crasto de Lima , R. H. Miwa , E. Vernek , G. J. Ferreira

We explore the effects of a heavy fermion doublet in a simplified version of the standard electroweak theory. We integrate out the doublet and compute the exact effective energy functional of spatially varying gauge and Higgs fields. We…

High Energy Physics - Theory · Physics 2009-11-10 E. Farhi , N. Graham , R. L. Jaffe , V. Khemani , H. Weigel

We present physical arguments based on loop space representations for Dirac/Klein gordon determinants that some suitable Fermionic String Ising models at the critical point and defined on the space-time base manifold are formal quantum…

General Relativity and Quantum Cosmology · Physics 2019-08-22 Luiz C. L. Botelho

Unlike the fundamental forces of the Standard Model the quantum effects of gravity are still experimentally inaccessible. Rather surprisingly quantum aspects of gravity, such as massive gravitons, can emerge in experiments with fractional…

Quantum Physics · Physics 2023-03-22 Patricio Salgado-Rebolledo , Jiannis K. Pachos

Loop Quantum Gravity provides a natural truncation of the infinite degrees of freedom of gravity, obtained by studying the theory on a given finite graph. We review this procedure and we present the construction of the canonical theory on a…

General Relativity and Quantum Cosmology · Physics 2012-03-27 Enrique F. Borja , Iñaki Garay , Francesca Vidotto

Starting from an heuristic approach to the semiclassical limit in loop quantum gravity, the construction of effective Hamiltonians describing Planck length corrections to the propagation of photons and spin 1/2 fermions, leading to modified…

High Energy Physics - Phenomenology · Physics 2016-11-09 Luis F. Urrutia

We propose a new method to quantize gauge theories formulated on a canonical noncommutative spacetime with fields and gauge transformations taken in the enveloping algebra. We show that the theory is renormalizable at one loop and compute…

High Energy Physics - Theory · Physics 2008-11-26 Xavier Calmet

We study gravity coupled to a scalar field in spherical symmetry using loop quantum gravity techniques. Since this model has local degrees of freedom, one has to face ``the problem of dynamics'', that is, diffeomorphism and Hamiltonian…

General Relativity and Quantum Cosmology · Physics 2009-11-19 Rodolfo Gambini , Jorge Pullin , Saeed Rastgoo

We present a fermion model characterized by an anticommuting-parameter shift symmetry. The Hamiltonian formulation exhibits a combination of first-class and second-class constraints. We derive the well-known Dirac equation by fixing the…

High Energy Physics - Theory · Physics 2023-06-30 Mauricio Valenzuela

We show that under certain technical assumptions, including the existence of a constant mean curvature (CMC) slice and strict positivity of the scalar field, general relativity conformally coupled to a scalar field can be quantised on a…

General Relativity and Quantum Cosmology · Physics 2013-04-25 Norbert Bodendorfer , Alexander Stottmeister , Andreas Thurn

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

I found an extended duality (triality) between Dirac fermions in periodic spacetime metrics, nonrelativistic fermions in gauge fields (e.g., Harper-Hofstadter model), and in periodic scalar fields on a lattice (e.g., Aubry-Andr\'e model).…

High Energy Physics - Lattice · Physics 2025-10-20 Pasquale Marra

In the investigation and resolution of the cosmological constant problem the inclusion of the dynamics of quantum gravity can be a crucial step. In this work we suggest that the quantum constraints in a canonical theory of gravity can…

High Energy Physics - Theory · Physics 2013-04-23 Jan Govaerts , Simone Zonetti

We derive the interaction of fermions with a dynamical space-time based on the postulate that the description of physics should be independent of the reference frame, which means to require the form-invariance of the fermion action under…

General Relativity and Quantum Cosmology · Physics 2021-08-31 Jürgen Struckmeier , David Vasak