Results 1 to 10 of about 6,253,661 (292)

`Operational' Energy Conditions [PDF]

Classical and Quantum Gravity, 1998
I show that a quantized Klein-Gordon field in Minkowski space obeys an `operational' weak energy condition: the energy of an isolated device constructed to measure or trap the energy in a region, plus the energy it measures or traps, cannot be negative ...
Adam D Helfer, Alcubierre M, Barton G, Barton G, Bohr N, Davies P C W, Epstein H, Flanagan E, Ford L H, Grove P G, Helfer A D, Morris M, Pfenning M J, Song Dae-Yup   +13 more
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Energy Conditions and Cosmic Acceleration [PDF]

Physical Review D, 2007
In general relativity, the energy conditions are invoked to restrict general energy-momentum tensors $T_{\mu\nu}$ in different frameworks, and to derive general results that hold in a variety of general contexts on physical grounds.
J. S. Alcaniz, J. Santos, M. J. Rebouças, M. Visser, M. Visser, N. Pires, S. Carroll, S. W. Hawking   +7 more
core   +4 more sources

Casimir Energies and General Relativity Energy Conditions [PDF]

Journal of Physics A: Mathematical and General, 2006
Quantum systems often contain negative energy densities. In general relativity, negative energies lead to time advancement, rather than the usual time delay. As a result, some Casimir systems appear to violate energy conditions that would protect against
Graham, N.
core   +2 more sources

Averaged Energy Conditions and Quantum Inequalities [PDF]

Physical Review D, 1994
Connections are uncovered between the averaged weak (AWEC) and averaged null (ANEC) energy conditions, and quantum inequality restrictions on negative energy for free massless scalar fields. In a two-dimensional compactified Minkowski universe, we derive
A. Borde, A. Borde, A. Borde, A. Borde, A. Folacci, C. I Kuo, F.J. Tipler, G. Klinkhammer, H. Epstein, H. Ford, H. Ford, H. Ford, H. Ford, H. Ford, H. Ford, H. Ford, H.B.G. Casimir, J. Friedman, L. A. Wu, L. H. Ford, L.S. Brown, M. Alcubierre, M. Morris, M. Morris, P.C.W. Davies, P.C.W. Davies, R. Penrose, R. Wald, S.A. Fulling, S.W. Hawking, S.W. Hawking, S.W. Hawking, S.W. Hawking, S.W. Kim, T.A. Roman, T.A. Roman, Thomas A. Roman, U. Yurtsever   +37 more
core   +5 more sources

Twilight for the energy conditions? [PDF]

International Journal of Modern Physics D, 2002
The tension, if not outright inconsistency, between quantum physics and general relativity is one of the great problems facing physics at the turn of the millennium.
Bekenstein J. B., Bronnikov K. A., CARLOS BARCELÓ, Ford L. H., Ford L. H., Hawking S. W., MATT VISSER   +6 more
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Energy Conditions and Supernovae Observations

Physical Review D, 2006
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 of state of ...
J. S. Alcaniz, J. Santos, M. J. Rebouças, M. Visser, S. Carroll, S. W. Hawking   +5 more
core   +2 more sources

Gravastar energy conditions revisited [PDF]

Classical and Quantum Gravity, 2007
We consider the gravastar model where the vacuum phase transition between the de Sitter interior and the Schwarzschild or Schwarzschild-de Sitter exterior geometries takes place at a single spherical delta-shell.
Andreasson H, Bilić N, Boehmer C G, Broderick A E, Carter B M N, Cattoen C, Chirenti C B M H Rezzolla L, DeBenedictis A, Dubravko Horvat, Dymnikova I, Ellis G F R Maartens R MacCallum M A H, Frauendiener J, Gliner E B, Hawking S W, Lobo F S N, Lobo F S N, Mazur P O Mottola E, Poisson E, Sakharov A D, Saša Ilijić, Visser M, Visser M   +21 more
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Averaged Energy Conditions and Bouncing Universes [PDF]

Physical Review D, 2017
The dynamics of bouncing universes is characterized by violating certain coordinate invariant restrictions on the total energy-momentum tensor, customarily referred to as energy conditions.
Giovannini, Massimo
core   +2 more sources

Presence and absence of intrinsic magnetism in graphitic carbon nitrides designed through C–N–H building blocks

Scientific Reports, 2022
We use the first principle calculation to investigate the intrinsic magnetism of graphitic carbon nitrides (GCNs). By preserving three-fold symmetry, the GCN building blocks have been built out of different combinations between 6 components which are C ...
Teerachote Pakornchote, Annop Ektarawong, Akkarach Sukserm, Udomsilp Pinsook, Thiti Bovornratanaraks   +4 more
doaj   +1 more source

Traversable Finslerian wormholes supported by phantom energy

Frontiers in Physics, 2023
This paper supplements the article (Eur. Phys. J. C 76: 246, 2016) by extending some more new wormhole solutions in the background of Finslerian geometry.
Ksh. Newton Singh, Farook Rahaman, Debabrata Deb, S. K. Maurya   +3 more
doaj   +1 more source