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Related papers: Fermions in Hybrid Loop Quantum Cosmology

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This is the second paper in a series of four in which we use space adiabatic methods in order to incorporate backreactions among the homogeneous and between the homogeneous and inhomogeneous degrees of freedom in quantum cosmological…

General Relativity and Quantum Cosmology · Physics 2019-06-20 J. Neuser , S. Schander , T. Thiemann

We numerically compute renormalized expectation values of quadratic operators in a quantum field theory (QFT) of free Dirac fermions in curved two-dimensional (Lorentzian) spacetime. First, we use a staggered-fermion discretization to…

General Relativity and Quantum Cosmology · Physics 2020-10-28 Adam G. M. Lewis , Guifré Vidal

Loop Quantum Gravity (L.Q.G.) is one of the two most promising tentative theory for a quantum description of gravity. When applied to the entire universe, the so-called Loop Quantum Cosmology (L.Q.C.) framework offers microscopical models…

General Relativity and Quantum Cosmology · Physics 2014-11-20 J. Grain

The usual description of inflationary fluctuations uses the framework of quantum field theory (QFT) in curved spacetime, in which quantum fluctuations are superimposed on a classical background spacetime. Even for large fluctuations, such…

General Relativity and Quantum Cosmology · Physics 2020-03-11 Sebastian F. Bramberger , Alice Di Tucci , Jean-Luc Lehners

We introduce a unique model for a fermion antifermion pair interacting through Dirac oscillator interaction in the presence of external uniform magnetic field. In order to acquire a non perturbative energy spectrum for such a system we…

General Physics · Physics 2021-02-10 Abdullah Guvendi

Quantum Information and the new informational paradigm are entering the domain of quantum field theory and gravity, suggesting the quantum automata framework. The quantum automaton is the minimal-assumption extension to the Planck and…

Quantum Physics · Physics 2012-11-13 Giacomo Mauro D'Ariano

The basic idea of the LQC applies to every spatially homogeneous cosmological model, however only the spatially flat (so called $k=0$) case has been understood in detail in the literature thus far. In the closed (so called: k=1) case…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Lukasz Szulc , Wojciech Kaminski , Jerzy Lewandowski

We discuss mimetic gravity theories with direct couplings between the curvature and higher derivatives of the scalar field, up to the quintic order, which were proposed to solve the instability problem for linear perturbations around the…

General Relativity and Quantum Cosmology · Physics 2019-12-18 Alexander Ganz , Nicola Bartolo , Sabino Matarrese

Representing massless Dirac fermions on a spatial lattice poses a potential challenge known as the Fermion Doubling problem. Addition of a quadratic term to the Dirac Hamiltonian circumvents this problem. We show that the modified…

Mesoscale and Nanoscale Physics · Physics 2015-09-15 K. M. Masum Habib , Redwan N. Sajjad , Avik W. Ghosh

We discuss the quantum dynamics of the Dirac fermion particle in a gauge gravitational field. The minimal as well as the Pauli-type nonminimal coupling of a fermion with external fields is studied, bringing into consideration the notions of…

High Energy Physics - Theory · Physics 2015-02-02 Yuri N. Obukhov , Alexander J. Silenko , Oleg V. Teryaev

Free scalar field theory on 2 dimensional flat spacetime, cast in diffeomorphism invariant guise by treating the inertial coordinates of the spacetime as dynamical variables, is quantized using LQG type `polymer' representations for the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alok Laddha , Madhavan Varadarajan

We discuss the low-energy dynamics of massless Dirac fermions interacting with a propagating, relativistic photon in 2+1 spacetime dimensions, when we turn on a uniform magnetic field. This problem can be solved when the magnetic field is…

High Energy Physics - Theory · Physics 2025-08-06 Thomas T. Dumitrescu , Juan Maldacena

A mathematical model is constructed for the evolution of spherical perturbations in a cosmological one-component statistical system of completely degenerate scalarly charged fermions with a scalar Higgs interaction. A complete system of…

General Relativity and Quantum Cosmology · Physics 2023-07-03 Yu. G. Ignat'ev

Dirac fermions, characterized by their linear dispersion and relativistic nature, have emerged as a prominent class of quasiparticles in condensed matter physics. While the Dirac equation, initially developed in the context of high-energy…

We study fractional quantum Hall states at filling fractions in the Jain sequences using the framework of composite Dirac fermions. Synthesizing previous work, we write down an effective field theory consistent with all symmetry…

Mesoscale and Nanoscale Physics · Physics 2018-05-31 Dung Xuan Nguyen , Siavash Golkar , Matthew M. Roberts , Dam Thanh Son

Loop quantum cosmology (LQC) predicts a nonsingular evolution of the universe through a bounce in the high energy region. We show that this is always true in tachyon matter LQC. Different from the classical Friedman-Robertson-Walker (FRW)…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Hua-Hui Xiong , Jian-Yang Zhu

We study one-loop corrections to the two-point correlation function of tensor perturbations in primordial cosmology induced by massless spectator matter fields. Using the Schwinger-Keldysh formalism in cosmological perturbation theory, we…

General Relativity and Quantum Cosmology · Physics 2020-11-02 H. S. Tan

We study the relations between massless Dirac fermions in an electromagnetic field and atoms in quantum optics. After getting the solutions of the energy spectrum, we show that it is possible to reproduce the 2D Dirac Hamiltonian, with all…

High Energy Physics - Theory · Physics 2015-05-27 Ahmed Jellal , Abderrahim El Mouhafid , Mohammed Daoud

This work is devoted to incorporating into QFT the notion that particles and hence the particle states should be localizable in space. It focuses on the case of the Dirac field in 1+1 dimensional flat spacetime, generalizing a recently…

Quantum Physics · Physics 2016-09-23 Aleksander M. Kubicki , Hans Westman , Juan Leon

We describe the free Dirac field in a four dimensional spacetime as a locally covariant quantum field theory in the sense of Brunetti, Fredenhagen and Verch, using a representation independent construction. The freedom in the geometric…

Mathematical Physics · Physics 2010-10-20 Ko Sanders