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Related papers: The fermionic double smeared null energy condition

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Quantum inequalities are constraints on how negative the weighted average of the renormalized stress-energy tensor of a quantum field can be. A null-projected quantum inequality can be used to prove the averaged null energy condition…

General Relativity and Quantum Cosmology · Physics 2015-12-16 Eleni-Alexandra Kontou , Ken D. Olum

By using a framework where the object of noncommutativity $\theta^{\mu\nu}$ represents independent degrees of freedom, we study the symmetry properties of an extended $x+\theta$ space-time, given by the group $P$', which has the…

High Energy Physics - Theory · Physics 2009-11-13 Ricardo Amorim

We present the electronic properties of massless Dirac fermions characterized by geometry and topology on a graphene sheet in this chapter. Topological effects can be elegantly illuminated by the Atiyah-Singer index theorem. It leads to a…

Strongly Correlated Electrons · Physics 2010-10-01 Kee-Su Park

We investigate the effects of a brane and magnetic-flux-carrying cosmic string on the vacuum expectation value (VEV) of the current density for a charged fermionic field in the background geometry of 4+1 dimensional anti-de Sitter (AdS)…

High Energy Physics - Theory · Physics 2021-03-17 S. Bellucci , W. Oliveira dos Santos , E. R. Bezerra de Mello , A. A. Saharian

In general relativity, the energy conditions are invoked to restrict general energy-momentum tensors on physical grounds. We show that in the standard Friedmann-Lemaitre-Robertson-Walker approach to cosmological modelling where the equation…

Astrophysics · Physics 2009-11-11 J. Santos , J. S. Alcaniz , M. J. Reboucas

The trace anomaly of quantum fields in electromagnetic or gravitational backgrounds implies the existence of massless scalar poles in physical amplitudes involving the stress-energy tensor. Considering first the axial anomaly and using QED…

High Energy Physics - Theory · Physics 2010-05-27 Maurizio Giannotti , Emil Mottola

A constraint of vanishing energy-momentum tensor is motivated by a variety of perspectives on quantum gravity. We demonstrate in a concrete example how this constraint leads to a metric-independent theory in which quantum gravity emerges as…

High Energy Physics - Theory · Physics 2017-04-26 Christopher D. Carone , Joshua Erlich , Diana Vaman

We investigate the fermionic properties of a dyonic Gubser-Rocha model in the context of gauge/gravity duality. This model incorporates both a magnetic field and momentum relaxation. We have derived this model's scaling exponent, revealing…

High Energy Physics - Theory · Physics 2024-12-31 Cheng-Yuan Lu , Xian-Hui Ge , Sang-Jin Sin

The renormalized energy density of a massless scalar field defined in a D-dimensional flat spacetime is computed in the presence of "soft" and "semihard" boundaries, modeled by some smoothly increasing potential functions. The sign of the…

High Energy Physics - Theory · Physics 2021-10-19 F. Caruso , R. De Paola , N. F. Svaiter

We devise a supersymmetry-based method for the construction of zero-energy states in graphene. Our method is applied to a two-dimensional massless Dirac equation with a hyperbolic scalar potential. We determine supersymmetric partners of…

Mathematical Physics · Physics 2017-09-13 Axel Schulze Halberg , Pinaki Roy

\noindent The well-known exact solution of the massless Schwinger model can be simply obtained by perturbing around a vacuum without the Dirac sea of filled negative energy states. The unusual vacuum structure changes the sign of the…

High Energy Physics - Phenomenology · Physics 2008-02-03 Paul Hoyer

The concept of Euclidean time is proposed which is dual to the usual Minkowski time. The De Sitter solution is shown to be dual to the anti-De Sitter solution under the dual transformation in which Euclidean time and Minkowski time are…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hirotaka Sugawara

This paper investigates the \emph{massive} Maxwell-Dirac system under the Lorenz gauge condition in (4+1) dimensional Minkowski space. The focus is on establishing global existence and scattering results for small solutions on the weighted…

Analysis of PDEs · Mathematics 2023-12-22 Kiyeon Lee

The massless Dirac fermions and the ease to introduce spatial and magnetic confinement in graphene provide us unprecedented opportunity to explore confined relativistic matter in this condensed-matter system. Here we report the interplay…

Mesoscale and Nanoscale Physics · Physics 2024-03-08 Ya-Ning Ren , Qiang Cheng , Chao Yan , Ke Lv , Mo-Han Zhang , Qing-Feng Sun , Lin He

Motivated by the physics of spin-orbital liquids, we study a model of interacting Dirac fermions on a bilayer honeycomb lattice at half filling, featuring an explicit global SO(3)$\times$U(1) symmetry. Using large-scale auxiliary-field…

Strongly Correlated Electrons · Physics 2022-02-25 Zi Hong Liu , Matthias Vojta , Fakher F. Assaad , Lukas Janssen

The vacuum expectation value (VEV) of the energy-momentum tensor for a massive fermionic field is investigated in a (2+1)-dimensional conical spacetime in the presence of a circular boundary and an infinitely thin magnetic flux located at…

High Energy Physics - Theory · Physics 2012-02-14 E. R. Bezerra de Mello , F. Moraes , A. A. Saharian

Various properties of the Misner-Sharp spherically symmetric gravitational energy E are established or reviewed. In the Newtonian limit of a perfect fluid, E yields the Newtonian mass to leading order and the Newtonian kinetic and potential…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Sean A. Hayward

The firm observational confirmation of the late-time acceleration of the universe expansion has proposed a major challenge to the theoretical foundations of cosmology and the explanation of the acceleration mechanism requires the…

General Relativity and Quantum Cosmology · Physics 2016-04-20 D Wang , Xin-He Meng

In a number of previous publications we demonstrated that the Two Measures Field Theory (TMT) enables to resolve the old cosmological constant (CC) problem avoiding the Weinberg's no-go CC theorem and together with this TMT agrees with all…

High Energy Physics - Theory · Physics 2007-08-05 E. I. Guendelman , A. B. Kaganovich

Using Visser's semi-analytical model for the stress-energy tensor corresponding to the conformally coupled massless scalar field in the Unruh vacuum, we examine, by explicitly evaluating the relevant integrals over half-complete geodesics,…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Hongwei Yu