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Related papers: Semi-local Bounds on Null Energy in QFT

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The classical singularity theorems of General Relativity rely on energy conditions that are easily violated by quantum fields. Here, we provide motivation for an energy condition obeyed in semiclassical gravity: the smeared null energy…

General Relativity and Quantum Cosmology · Physics 2021-10-25 Eleni-Alexandra Kontou , Ben Freivogel , Dimitrios Krommydas

We give a simplified approach to Kunzinger & Saemann's theory of Lorentzian length spaces in the globally hyperbolic case; these provide a nonsmooth framework for general relativity. We close a gap in the regularly localizable setting, by…

General Relativity and Quantum Cosmology · Physics 2023-09-26 Robert J. McCann

The quantum well solar cell (QWSC) has been proposed as a flexible means to ensuring current matching for tandem cells. This paper explores the further advantage afforded by the indication that QWSCs operate in the radiative limit because…

Mesoscale and Nanoscale Physics · Physics 2010-06-10 J. P. Connolly , I. M. Ballard , K. W. J. Barnham , D. B. Bushnell , T. N. D. Tibbits , J. S. Roberts

Employing universal relations for the Onsager coefficients in the linear regime at the symmetric point of the single impurity Anderson model, we calculate the conditions under which the quantum scattering phase shift should satisfy to…

Mesoscale and Nanoscale Physics · Physics 2024-05-03 R. S. Cortes-Santamaria , J. A. Landazabal-Rodríguez , J. Silva-Valencia , E. Ramos , M. S. Figueira , R. Franco

The quantum null energy condition (QNEC) is a lower bound on the energy-momentum tensor in terms of the variation of the entanglement entropy of a sub-region along a null direction. To gain insights into quantum thermodynamics of many-body…

High Energy Physics - Theory · Physics 2022-05-11 Tanay Kibe , Ayan Mukhopadhyay , Pratik Roy

Recently, Larry Ford and Tom Roman have discovered that in a flat cylindrical space, although the stress-energy tensor itself fails to satisfy the averaged null energy condition (ANEC) along the (non-achronal) null geodesics, when the…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Ulvi Yurtsever

In QFT, the null energy condition (NEC) for a classical field configuration is usually associated with that configuration's stability against small perturbations, and with the sub-luminality of these. Here, we exhibit an effective field…

High Energy Physics - Theory · Physics 2012-09-18 Alberto Nicolis , Riccardo Rattazzi , Enrico Trincherini

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

For a real quadratic field $\mathbb{Q}(\sqrt{d})$, we study the norm-form energy $N = S_\zeta^2 - d \cdot S_L^2$, where $S_\zeta$ and $S_L$ are Lorentzian-weighted zero sums with $w(\rho) = 2/(\tfrac{1}{4} + \gamma^2)$. We prove three main…

Number Theory · Mathematics 2026-03-13 Peter Shiller

We study the Null Energy Condition (NEC) arising from the Virasoro constraint on the string worldsheet. We then analyze how the NEC in the external spacetime directions emerges under general time-dependent string compactifications. Finally,…

High Energy Physics - Theory · Physics 2026-03-13 Mir Mehedi Faruk

In this paper we investigate the energy distribution of states of a linear scalar quantum field with arbitrary curvature coupling on a curved spacetime which fulfill some local thermality condition. We find that this condition implies a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jan Schlemmer , Rainer Verch

Field theories which violate the null energy condition (NEC) are of interest for the solution of the cosmological singularity problem and for models of cosmological dark energy with the equation of state parameter $w<-1$. We discuss the…

High Energy Physics - Theory · Physics 2008-11-26 I. Ya. Aref'eva , I. V. Volovich

The Averaged Null Energy Condition (ANEC) requires that the average along a complete null geodesic of the projection of the stress-energy tensor onto the geodesic tangent vector can never be negative. It is sufficient to rule out many…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Christopher J. Fewster , Ken D. Olum , Michael J. Pfenning

Recently a restriction ("quantum inequality-type relation") on the (renormalized) energy density measured by a static observer in a "globally static" (ultrastatic) spacetime has been formulated by Pfenning and Ford for the minimally coupled…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Dae-Yup Song

Averaged Null Energy Conditions (ANECs) hold in unitary quantum field theories. In conformal field theories, ANECs in states created by the application of the stress tensor to the vacuum lead to three constraints on the stress-tensor…

High Energy Physics - Theory · Physics 2023-05-31 Kuo-Wei Huang , Robin Karlsson , Andrei Parnachev , Samuel Valach

The energy conditions play an important role in the understanding of several properties of the Universe, including the current accelerating expansion phase and the possible existence of the so-called phantom fields. We show that the…

Astrophysics · Physics 2009-06-23 M. P. Lima , S. Vitenti , M. J. Reboucas

Energy is at best defined quasilocally in general relativity. Quasilocal energy definitions depend on the conditions one imposes on the boundary Hamiltonian, i.e., how a finite region of spacetime is "isolated". Here, we propose a method to…

General Relativity and Quantum Cosmology · Physics 2016-10-19 Nezihe Uzun

Considerable interest has recently been expressed regarding the issue of whether or not quantum field theory on a fixed but curved background spacetime satisfies the averaged null energy condition (ANEC). A comment by Wald and Yurtsever…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Matt Visser

We theoretically investigate the quantum phase transition in the collective systems of qubits in a high-quality cavity, which is driven by a squeezed light. We show that the squeezed light induced symmetry breaking can result in quantum…

Quantum Physics · Physics 2020-02-26 Chengjie Zhu , Leilei Ping , Yaping Yang , Girish S. Agarwal

We examine the achronal averaged null energy condition~(ANEC) for a class of conformal field theories~(CFT) at strong coupling in curved spacetime. By applying the AdS/CFT duality, we find holographic models which violate the achronal ANEC…

High Energy Physics - Theory · Physics 2019-09-11 Akihiro Ishibashi , Kengo Maeda , Eric Mefford