scholarly journals New results on vacuum fluctuations: Accelerated detector versus inertial detector in a quantum field

2021 ◽  
Vol 104 (4) ◽  
Author(s):  
I-Chin Wang
Keyword(s):  
Quantum Field ◽  
Vacuum Fluctuations

scholarly journals NEGATIVE ENERGY DENSITIES IN QUANTUM FIELD THEORY

2010 ◽  
Vol 25 (11) ◽  
pp. 2355-2363 ◽  
Author(s):  
L. H. FORD
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Energy Density ◽  
Negative Energy ◽  
Mean Value ◽  
Quantum Field ◽  
Two Dimensional ◽  
Vacuum Fluctuations ◽  
Negative Energy Density ◽  
Dimensional Spacetime

Quantum field theory allows for the suppression of vacuum fluctuations, leading to sub-vacuum phenomena. One of these is the appearance of local negative energy density. Selected aspects of negative energy will be reviewed, including the quantum inequalities which limit its magnitude and duration. However, these inequalities allow the possibility that negative energy and related effects might be observable. Some recent proposals for experiments to search for sub-vacuum phenomena will be discussed. Fluctuations of the energy density around its mean value will also be considered, and some recent results on a probability distribution for the energy density in two dimensional spacetime are summarized.

scholarly journals Background independent quantum field theory and gravitating vacuum fluctuations

2019 ◽  
Vol 411 ◽  
pp. 167972 ◽  
Author(s):  
Carlo Pagani ◽  
Martin Reuter
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Quantum Field ◽  
Vacuum Fluctuations

scholarly journals Quantum electromagnetic phenomena far from small evaporating black holes

2016 ◽  
Vol 12 (S324) ◽  
pp. 279-282 ◽  
Author(s):  
Slava Emelyanov
Keyword(s):  
Black Holes ◽  
Minkowski Space ◽  
Quantum Electrodynamics ◽  
Experimental Tests ◽  
Quantum Field ◽  
Vacuum Fluctuations ◽  
Quantum Processes ◽  
Weak Gravity

AbstractOne might expect far away from physical black holes that quantum field quantisation performed in Minkowski space is a good approximation. Indeed, all experimental tests in particle colliders reveal no deviations so far. Nevertheless, the black holes should leave certain imprints of their presence in quantum processes. In this paper, we shall discuss several local imprints of small, primordial evaporating black holes in quantum electrodynamics in the weak gravity regime. Physically this can be interpreted as being macroscopic manifestations of vacuum fluctuations.

scholarly journals How to hide a cosmological constant

2019 ◽  
Vol 28 (14) ◽  
pp. 1943004 ◽  
Author(s):  
Steven Carlip
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Cosmological Constant ◽  
Planck Scale ◽  
Quantum Field ◽  
Vacuum Fluctuations ◽  
And Topology ◽  
Spacetime Foam

Naive calculations in quantum field theory suggest that vacuum fluctuations should induce an enormous cosmological constant. What if these estimates are right? I argue that even a huge cosmological constant might be hidden in Planck-scale fluctuations of geometry and topology — what Wheeler called “spacetime foam” — while remaining virtually invisible macroscopically.

scholarly journals Atom-Field Interaction: From Vacuum Fluctuations to Quantum Radiation and Quantum Dissipation or Radiation Reaction

Physics ◽  
2019 ◽  
Vol 1 (3) ◽  
pp. 430-444 ◽  
Author(s):  
Jen-Tsung Hsiang ◽  
B. L. Hu
Keyword(s):  
Degrees Of Freedom ◽  
Mutual Influence ◽  
Equations Of Motion ◽  
Free Field ◽  
Radiation Reaction ◽  
Linear Response Theory ◽  
Quantum Field ◽  
Quantum Dissipation ◽  
Vacuum Fluctuations ◽  
Quantum Radiation

In this paper, we dwell on three issues: (1) revisit the relation between vacuum fluctuations and radiation reaction in atom-field interactions, an old issue that began in the 1970s and settled in the 1990s with its resolution recorded in monographs; (2) the fluctuation–dissipation relation (FDR) of the system, pointing out the differences between the conventional form in linear response theory (LRT) assuming ultra-weak coupling between the system and the bath, and the FDR in an equilibrated final state, relaxed from the nonequilibrium evolution of an open quantum system; (3) quantum radiation from an atom interacting with a quantum field: We begin with vacuum fluctuations in the field acting on the internal degrees of freedom (idf) of an atom, adding to its dynamics a stochastic component which engenders quantum radiation whose backreaction causes quantum dissipation in the idf of the atom. We show explicitly how different terms representing these processes appear in the equations of motion. Then, using the example of a stationary atom, we show how the absence of radiation in this simple cases is a result of complex cancellations, at a far away observation point, of the interference between emitted radiation from the atom and the local fluctuations in the free field. In so doing we point out in Issue 1 that the entity which enters into the duality relation with vacuum fluctuations is not radiation reaction, which can exist as a classical entity, but quantum dissipation. Finally, regarding issue 2, we point out for systems with many atoms, the co-existence of a set of correlation-propagation relations (CPRs) describing how the correlations between the atoms are related to the propagation of their (retarded non-Markovian) mutual influence manifesting in the quantum field. The CPR is absolutely crucial in keeping the balance of energy flows between the constituents of the system, and between the system and its environment. Without the consideration of this additional relation in tether with the FDR, dynamical self-consistency cannot be sustained. A combination of these two sets of relations forms a generalized matrix FDR relation that captures the physical essence of the interaction between an atom and a quantum field at arbitrary coupling strength.

scholarly journals Accelerated detector-quantum field correlations: From vacuum fluctuations to radiation flux

2006 ◽  
Vol 73 (12) ◽  
Author(s):  
Shih-Yuin Lin ◽  
B. L. Hu
Keyword(s):  
Radiation Flux ◽  
Quantum Field ◽  
Vacuum Fluctuations

scholarly journals EXPLORING QUANTUM VACUUM WITH LOW-ENERGY PHOTONS

2012 ◽  
Vol 10 (08) ◽  
pp. 1241002 ◽  
Author(s):  
E. MILOTTI ◽  
F. DELLA VALLE ◽  
G. ZAVATTINI ◽  
G. MESSINEO ◽  
U. GASTALDI ◽  
...  
Keyword(s):  
Cross Section ◽  
Gamma Rays ◽  
Quantum Electrodynamics ◽  
Low Energy ◽  
Quantum Field ◽  
Quantum Vacuum ◽  
Vacuum Fluctuations ◽  
Photon Scattering ◽  
Electronic Field ◽  
Photon Cross Section

Although quantum mechanics (QM) and quantum field theory (QFT) are highly successful, the seemingly simplest state — vacuum — remains mysterious. While the LHC experiments are expected to clarify basic questions on the structure of QFT vacuum, much can still be done at lower energies as well. For instance, experiments like PVLAS try to reach extremely high sensitivities, in their attempt to observe the effects of the interaction of visible or near-visible photons with intense magnetic fields — a process which becomes possible in quantum electrodynamics (QED) thanks to the vacuum fluctuations of the electronic field, and which is akin to photon–photon scattering. PVLAS is now close to data-taking and if it reaches the required sensitivity, it could provide important information on QED vacuum. PVLAS and other similar experiments face great challenges as they try to measure an extremely minute effect. However, raising the photon energy greatly increases the photon–photon cross section, and gamma rays could help extract much more information from the observed light–light scattering. Here we discuss an experimental design to measure photon–photon scattering close to the peak of the photon–photon cross section, that could fit in the proposed construction of an FEL facility at the Cabibbo Lab near Frascati (Rome, Italy).

scholarly journals The case for a Casimir cosmology

2020 ◽  
Vol 378 (2177) ◽  
pp. 20190229 ◽  
Author(s):  
Ulf Leonhardt
Keyword(s):  
New York ◽  
Cosmological Constant ◽  
Casimir Effect ◽  
Quantum Field ◽  
Vacuum Fluctuations ◽  
Correct Order ◽  
Dielectric Media ◽  
Analogue Gravity ◽  
Lifshitz Theory ◽  
Order Of Magnitude

The cosmological constant, also known as dark energy, was believed to be caused by vacuum fluctuations, but naive calculations give results in stark disagreement with fact. In the Casimir effect, vacuum fluctuations cause forces in dielectric media, which is very well described by Lifshitz theory. Recently, using the analogy between geometries and media, a cosmological constant of the correct order of magnitude was calculated with Lifshitz theory (Leonhardt 2019 Ann. Phys. ( New York ) 411 , 167973. ( doi:10.1016/j.aop.2019.167973 )). This paper discusses the empirical evidence and the ideas behind the Lifshitz theory of the cosmological constant without requiring prior knowledge of cosmology and quantum field theory. This article is part of a discussion meeting issue ‘The next generation of analogue gravity experiments’.

Factorization Algebras in Quantum Field Theory

2016 ◽  
Author(s):  
Kevin Costello ◽  
Owen Gwilliam
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Quantum Field ◽  
Factorization Algebras
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