scholarly journals Stochastic theory of relativistic particles moving in a quantum field: Scalar Abraham-Lorentz-Dirac-Langevin equation, radiation reaction, and vacuum fluctuations

2002 ◽  
Vol 65 (6) ◽  
Author(s):  
Philip R. Johnson ◽  
B. L. Hu
Keyword(s):  
Langevin Equation ◽  
Stochastic Theory ◽  
Radiation Reaction ◽  
Quantum Field ◽  
Vacuum Fluctuations ◽  
Relativistic Particles

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.

EFFECTS OF A BOUNDARY ON SPONTANEOUS EXCITATION OF AN ACCELERATED MULTILEVEL ATOM COUPLED WITH THE DERIVATIVE OF SCALAR FIELDS

2007 ◽  
Vol 22 (20) ◽  
pp. 3447-3461
Author(s):  
YUNFENG ZHU ◽  
HONGWEI YU
Keyword(s):  
Radiation Reaction ◽  
Scalar Fields ◽  
Normal Direction ◽  
Coupling Scheme ◽  
Quantum Fields ◽  
Vacuum Fluctuations ◽  
Direction Parallel ◽  
Excitation Rate ◽  
Derivative Coupling ◽  
Multilevel Atom

The presence of boundaries modifies the modes of quantum fields, which may in turn modifies the spontaneous excitation rate of accelerated atoms in interaction with these fields. In this paper, we study the effect of the presence of a reflecting boundary on the spontaneous excitation of a uniformly accelerated polarized multilevel atom interacting with quantum scalar fields in a dipole-derivative coupling scheme. We separately calculate the contributions of modified vacuum fluctuations and the radiation reaction to the spontaneous excitation rate of the atom. Our results show that the presence of the boundary modulates the excitation rate and makes it a function of the atom's distance from the boundary. When the atom is placed closer and closer to the boundary, the influence of the boundary becomes more and more drastic, with the contribution of the atom's polarization in the direction parallel to the boundary to the spontaneous excitation rate dramatically suppressed while that in the normal direction greatly enhanced.

scholarly journals Stochastic theory of accelerated detectors in a quantum field

1996 ◽  
Vol 53 (12) ◽  
pp. 7003-7019 ◽  
Author(s):  
Alpan Raval ◽  
B. L. Hu ◽  
James Anglin
Keyword(s):  
Stochastic Theory ◽  
Quantum Field

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 Infinite dimensional Langevin equation and Fokker-Planck equation

1981 ◽  
Vol 81 ◽  
pp. 177-223 ◽  
Author(s):  
Yoshio Miyahara
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Hilbert Space ◽  
Partial Differential Equations ◽  
Langevin Equation ◽  
Planck Equation ◽  
Theory Theory ◽  
Quantum Field ◽  
Filtering Theory ◽  
Infinite Dimensional

Stochastic processes on a Hilbert space have been discussed in connection with quantum field theory, theory of partial differential equations involving random terms, filtering theory in electrical engineering and so forth, and the theory of those processes has greatly developed recently by many authors (A. B. Balakrishnan [1, 2], Yu. L. Daletskii [7], D. A. Dawson [8, 9], Z. Haba [12], R. Marcus [18], M. Yor [26]).

scholarly journals Vacuum fluctuations and radiation reaction : identification of their respective contributions

1982 ◽  
Vol 43 (11) ◽  
pp. 1617-1638 ◽  
Author(s):  
J. Dalibard ◽  
J. Dupont-Roc ◽  
C. Cohen-Tannoudji
Keyword(s):  
Radiation Reaction ◽  
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.

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