Journal articles: 'Quantum electrodynamic theory'

1

Boyer, Timothy. "Stochastic Electrodynamics: The Closest Classical Approximation to Quantum Theory." Atoms 7, no. 1 (March 1, 2019): 29. http://dx.doi.org/10.3390/atoms7010029.

Full text

Abstract:

Stochastic electrodynamics is the classical electrodynamic theory of interacting point charges which includes random classical radiation with a Lorentz-invariant spectrum whose scale is set by Planck’s constant. Here, we give a cursory overview of the basic ideas of stochastic electrodynamics, of the successes of the theory, and of its connections to quantum theory.

APA, Harvard, Vancouver, ISO, and other styles

2

Shabaev, V. M. "Quantum electrodynamic theory of multiply charged ions." Soviet Physics Journal 33, no. 8 (August 1990): 660–70. http://dx.doi.org/10.1007/bf00892300.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Fujikawa, Takashi, and Hiroko Arai. "Nonrelativistic quantum electrodynamic approach to photoemission theory." Journal of Electron Spectroscopy and Related Phenomena 149, no. 1-3 (November 2005): 61–86. http://dx.doi.org/10.1016/j.elspec.2005.07.003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Keller, Ole, and Lee M. Hively. "Electrodynamics in curved space-time: Free-space longitudinal wave propagation." Physics Essays 32, no. 3 (September 11, 2019): 282–91. http://dx.doi.org/10.4006/0836-1398-32.3.282.

Full text

Abstract:

Jiménez and Maroto [Phys. Rev. D 83, 023514 (2011)] predicted free-space, longitudinal electrodynamic waves in curved space-time, if the Lorenz condition is relaxed. A general-relativistic extension of Woodside’s electrodynamics [Am. J. Phys. 77, 438 (2009)] includes a dynamical, scalar field in both the potential- and electric/magnetic-field formulations without mixing the two. We formulate a longitudinal-wave theory, eliminating curvature polarization, magnetization density, and scalar field in favor of the electric/magnetic fields and the metric tensor. We obtain a wave equation for the longitudinal electric field for a spatially flat, expanding universe with a scale factor. This work is important, because: (i) the scalar- and longitudinal-fields do not cancel, as in classical quantum electrodynamics; and (ii) this new approach provides a first-principles path to an extended quantum theory that includes acceleration and gravity.

APA, Harvard, Vancouver, ISO, and other styles

5

Iqbal, Saleem, Muhammad Zafar, Farhana Sarwar, Syed Mohsin Raza, and Muhammad Afzal Rana. "Application of Electrodynamic Theory on Quantum Hall Effect." World Journal of Condensed Matter Physics 06, no. 02 (2016): 87–94. http://dx.doi.org/10.4236/wjcmp.2016.62012.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Gordov, E. P., and A. Z. Fazliev. "Quantum electrodynamic perturbation theory based on semiclassical representation." Journal of Mathematical Physics 26, no. 6 (June 1985): 1261–63. http://dx.doi.org/10.1063/1.526932.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Philip, Timothy M., and Matthew J. Gilbert. "Theory of AC quantum transport with fully electrodynamic coupling." Journal of Computational Electronics 17, no. 3 (May 21, 2018): 934–48. http://dx.doi.org/10.1007/s10825-018-1191-z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Widom, A., Y. N. Srivastava, C. Vittoria, H. How, R. Karim, and H. Jiang. "Quantum-electrodynamic theory of vortex oscillations in type-II superconductors." Physical Review B 46, no. 2 (July 1, 1992): 1102–6. http://dx.doi.org/10.1103/physrevb.46.1102.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

SALAM, A. "A quantum electrodynamic theory of two-centre two-photon circular dichroism." Molecular Physics 99, no. 4 (February 20, 2001): 267–73. http://dx.doi.org/10.1080/00268970010008360.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

KELLER, OLE. "NONLINEAR OPTICS IN THE NEAR-FIELD ZONE OF ATOMS." Journal of Nonlinear Optical Physics & Materials 11, no. 03 (September 2002): 275–301. http://dx.doi.org/10.1142/s0218863502001048.

Full text

Abstract:

Elements of a new quantum electrodynamic theory which might enable one to obtain a better understanding of the linear and nonlinear interaction between atomic systems in near-field contact is presented. To follow the space-time dynamics in the atomic near-field zone an electromagnetic propagator formalism with polychromatic photons is constructed. A first-quantized description based on the photon energy wave function for free polychromatic photons is extended in such a manner that the birth process of the photon, which takes place in the near-field zone of the source, can be followed. In order to be able to describe harmonic generation processes in near-field optics polychromatic photons of the simple wave-train type are used. The wave mechanical (first-quantized) description based on wave-train photons is upgraded to a field-theoretic (second-quantized) formalism using a new so-called propagator gauge which is closely related to the Poincaré gauge underlying the multipole description of quantum electrodynamics.

APA, Harvard, Vancouver, ISO, and other styles

11

Domnitch, Evelina, Dmitry Gelfand, and Tommaso Calarco. "Trapping the Objectless." Leonardo 52, no. 1 (February 2019): 68–69. http://dx.doi.org/10.1162/leon_a_01465.

Full text

Abstract:

Through the epistemological lenses of quantum theory and phenomenological art, the authors describe their collaborative development of several artworks exploring electrodynamic levitation. Comprising diverse ion traps that enable naked-eye observation of charged matter interactions, these artworks question the murky boundaries of perceptibility and objectification.

APA, Harvard, Vancouver, ISO, and other styles

12

Yannopapas, Vassilios. "An atomistic-electrodynamics theory for the optical response of periodic lattices of metallic nanoparticles in the quantum size regime." International Journal of Modern Physics B 31, no. 24 (September 30, 2017): 1740001. http://dx.doi.org/10.1142/s021797921740001x.

Full text

Abstract:

We present a new theoretical method for calculating the optical properties of periodic arrays of metallic nanoparticles whose dimensions are in the quantum-size limit and cannot, therefore, be described by macroscopic electrodynamic theory based on Maxwell’s equations. In the first stage, the method calculates the scattering matrix for a single metal nanoparticle described as a polyhedral cluster of atoms, via a discrete-dipole approximation/point-matching technique. The resulting scattering matrix is incorporated into a layer-multiple-scattering technique which allows the modeling of two- and three-dimensional nanostructures containing very small metal nanoparticles. The method is demonstrated for square arrays of silver nanoparticles with radii below 2 nm and the corresponding results are compared against classical local and nonlocal electrodynamic approaches.

APA, Harvard, Vancouver, ISO, and other styles

13

Cour, Brian R. La, and Morgan C. Williamson. "Emergence of the Born rule in quantum optics." Quantum 4 (October 26, 2020): 350. http://dx.doi.org/10.22331/q-2020-10-26-350.

Full text

Abstract:

The Born rule provides a fundamental connection between theory and observation in quantum mechanics, yet its origin remains a mystery. We consider this problem within the context of quantum optics using only classical physics and the assumption of a quantum electrodynamic vacuum that is real rather than virtual. The connection to observation is made via classical intensity threshold detectors that are used as a simple, deterministic model of photon detection. By following standard experimental conventions of data analysis on discrete detection events, we show that this model is capable of reproducing several observed phenomena thought to be uniquely quantum in nature, thus providing greater elucidation of the quantum-classical boundary.

APA, Harvard, Vancouver, ISO, and other styles

14

LEHNERT, BO. "On angular momentum and rest mass of the photon." Journal of Plasma Physics 79, no. 6 (December 2013): 1133–35. http://dx.doi.org/10.1017/s002237781300069x.

Full text

Abstract:

AbstractA reconsideration is made on the basic concepts of the individual photon, including its angular momentum (spin) and a possibly existing very small rest mass. In terms of conventional classical theory, as well as of its quantum mechanical counterpart, the results from a so far established Standard Model of an empty vacuum state are not found to be reconcilable with an experimentally relevant photon model. The main properties of such a model would on the other hand become compatible with the results of a recently established revised quantum electrodynamic theory based on a non-zero electric field divergence in the vacuum and a corresponding symmetry breaking of the electromagnetic field.

APA, Harvard, Vancouver, ISO, and other styles

15

Zheng, Yi. "A Generalization of Electromagnetic Fluctuation-Induced Casimir Energy." Advances in Condensed Matter Physics 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/198657.

Full text

Abstract:

Intermolecular forces responsible for adhesion and cohesion can be classified according to their origins; interactions between charges, ions, random dipole—random dipole (Keesom), random dipole—induced dipole (Debye) are due to electrostatic effects; covalent bonding, London dispersion forces between fluctuating dipoles, and Lewis acid-base interactions are due to quantum mechanical effects; pressure and osmotic forces are of entropic origin. Of all these interactions, the London dispersion interaction is universal and exists between all types of atoms as well as macroscopic objects. The dispersion force between macroscopic objects is called Casimir/van der Waals force. It results from alteration of the quantum and thermal fluctuations of the electrodynamic field due to the presence of interfaces and plays a significant role in the interaction between macroscopic objects at micrometer and nanometer length scales. This paper discusses how fluctuational electrodynamics can be used to determine the Casimir energy/pressure between planar multilayer objects. Though it is confirmation of the famous work of Dzyaloshinskii, Lifshitz, and Pitaevskii (DLP), we have solved the problem without having to use methods from quantum field theory that DLP resorted to. Because of this new approach, we have been able to clarify the contributions of propagating and evanescent waves to Casimir energy/pressure in dissipative media.

APA, Harvard, Vancouver, ISO, and other styles

16

Shabaev, V. M. "Quantum electrodynamic theory of recombination of an electron with a highly charged ion." Physical Review A 50, no. 6 (December 1, 1994): 4521–34. http://dx.doi.org/10.1103/physreva.50.4521.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Pal'chikov, V. G., I. Yu Skobelev, and A. Ya Faenov. "Testing of QED theory on the Rydberg series for the He-like multicharged ions." Canadian Journal of Physics 80, no. 11 (November 1, 2002): 1255–61. http://dx.doi.org/10.1139/p02-091.

Full text

Abstract:

The paper examines the 1/Z expansion method in calculating the energy levels, ionization energies, and wavelengths of the resonant Rydberg states 1snp 1P1 for atoms belonging to the helium isoelectronic sequence. The interactions of the bound electrons are treated as a perturbation that results in the electronelectron Breit interaction, relativistic corrections, and quantum electrodynamic (QED) contributions. By comparing the calculated wavelengths with a number of observed wavelengths, the QED contributions to the ground state are analyzed. PACS Nos.: 31.20Di, 31.20Tz, 31.30Jv, 31.50+W

APA, Harvard, Vancouver, ISO, and other styles

18

Yu, Chao, Jingtao Zhang, Zhi-Wei Sun, Zhenrong Sun, and Dong-Sheng Guo. "A nonperturbative quantum electrodynamic approach to the theory of laser induced high harmonic generation." Frontiers of Physics 10, no. 4 (August 5, 2014): 1–6. http://dx.doi.org/10.1007/s11467-014-0429-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Kosobukin, V. A. "Plasmon-excitonic polaritons in metal-semiconductor nanostructures with quantum wells." Физика и техника полупроводников 52, no. 5 (2018): 502. http://dx.doi.org/10.21883/ftp.2018.05.45846.35.

Full text

Abstract:

AbstractA theory of plasmon-exciton coupling and its spectroscopy is developed for metal-semiconductor nanostructures. Considered as a model is a periodic superlattice with cells consisting of a quantum well and a layer of metal nanoparticles. The problem is solved self-consistently using the electrodynamic Green’s functions taking account of resonant polarization. Coulomb plasmon-exciton interaction is associated with the dipole surface plasmons of particles and their image charges due to excitonic polarization of neighboring quantum well. Optical reflection spectra are numerically investigated for superlattices with GaAs/AlGaAs quantum wells and silver nanoparticles. Superradiant regime caused by one-dimensional Bragg diffraction is studied for plasmonic, excitonic and plasmon-excitonic polaritons depending on the number of supercells. The plasmon-excitonic Rabi splitting is shown to occur in reflectivity spectra of resonant Bragg structures.

APA, Harvard, Vancouver, ISO, and other styles

20

LEHNERT, B., and L. J. HÖÖK. "An electron model with elementary charge." Journal of Plasma Physics 76, no. 3-4 (January 25, 2010): 419–28. http://dx.doi.org/10.1017/s0022377809990638.

Full text

Abstract:

AbstractAn earlier elaborated model of the electron, being based on a revised quantum electrodynamic theory, is further investigated in terms of an improved numerical iteration scheme. This point-charge-like model is based on the “infinity” of a divergent generating function being balanced by the “zero” of a shrinking characteristic radius. This eliminates the self-energy problem. According to the computations, the quantum conditions on spin, magnetic moment, and magnetic flux, plus the requirement of an elementary charge having the experimental value, can all be satisfied within rather narrow limits by a single scalar parameter. The revised model prevents the electron from “exploding” due to its eigencharge.

APA, Harvard, Vancouver, ISO, and other styles

21

Cheng, K. T., M. H. Chen, W. R. Johnson, and J. Sapirstein. "High-precision relativistic atomic structure calculations and the EBIT: Tests of quantum electrodynamics in highly charged ions." Canadian Journal of Physics 86, no. 1 (January 1, 2008): 33–43. http://dx.doi.org/10.1139/p07-106.

Full text

Abstract:

High-precision relativistic atomic-structure calculations based on the relativistic many-body perturbation theory and the relativistic configuration-interaction method are shown to provide stringent tests of strong-field quantum electrodynamic (QED) corrections when compared with electron beam ion trap measurements of the spectra of highly charged, many-electron ions. It is further shown that theory and experiment are accurate enough to test not just the leading screened QED corrections but also smaller contributions from higher order Breit interactions, relaxed-core QED corrections, two-loop Lamb shifts, negative-energy state corrections, nuclear polarizations, and nuclear recoils. PACS Nos. 31.30.Jv, 32.30.Rj, 31.25.–v, 31.15.Ar

APA, Harvard, Vancouver, ISO, and other styles

22

Daywitt, William C. "The Anomalous Magnetic Moment of the Electron and Proton Cores According to the Planck Vacuum Theory." European Journal of Engineering Research and Science 4, no. 6 (June 26, 2019): 117–19. http://dx.doi.org/10.24018/ejers.2019.4.6.1379.

Full text

Abstract:

Despite the resounding success of the quantum electrodynamic (QED) calculations, there remains some confusion concerning the Dirac equation’s part in the calculation of the anomalous magnetic moment of the electron and proton. The confusion resides in the nature of the Dirac equation, the fine structure constant, and the relationship between the two. This paper argues that the Dirac equation describes the coupling of the electron or proton cores to the invisible Planck vacuum (PV) state (involving e2 ); and that the fine structure constant ( = e2/e2 ) connects that equation to the electron or proton particles measured in the laboratory (involving e2).

APA, Harvard, Vancouver, ISO, and other styles

23

Jentschura, Ulrich D., Peter J. Mohr, Joseph N. Tan, and Benedikt J. Wundt. "Fundamental constants and tests of theory in Rydberg states of hydrogenlike ionsThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at University of Windsor, Windsor, Ontario, Canada on 21–26 July 2008." Canadian Journal of Physics 87, no. 7 (July 2009): 757–62. http://dx.doi.org/10.1139/p08-118.

Full text

Abstract:

A comparison of precision frequency measurements to quantum electrodynamic (QED) theoretical predictions can be used to test theory and to obtain information regarding fundamental constants. We find that for Rydberg states, theoretical uncertainties due to the problematic nuclear size correction are very small. With the help of QED calculations, the largest remaining source of uncertainty can be eliminated. Theoretical predictions, taking advantage of the latest theoretical results, in combination with planned experiments, can lead to an improved value for the Rydberg constant.

APA, Harvard, Vancouver, ISO, and other styles

24

YINNON, CARMI A., and TAMAR A. YINNON. "DOMAINS IN AQUEOUS SOLUTIONS: THEORY AND EXPERIMENTAL EVIDENCE." Modern Physics Letters B 23, no. 16 (June 30, 2009): 1959–73. http://dx.doi.org/10.1142/s0217984909020138.

Full text

Abstract:

Experimentally observed aggregates in under-saturated aqueous solutions are analyzed. Aggregates studied include: 0.5 to 6 micrometer-sized domains composed of solvated strong electrolyte ions, organic- or bio-molecules; clusters of up to 280 water molecules. Hitherto, the customary electrostatic (ES) theories could not explain the formation of these large aggregates. Recently, it was shown that quantum electrodynamic (QED) interactions might affect the structure of solutions. Our analysis indicates that these interactions cause the observed aggregations. We found the observed aggregate characteristics conform to those of QED coherent domains. For example, QED predicts that dilution, e.g. from 2 M to 1 M, causes an increase of several hundred percent in the size of domains composed of solvated coherently oscillating molecules or ions. For solutions of DNA or NaCl , the measured cluster size as a function of concentration is available in the literature. We found it to be in agreement with the QED predictions.

APA, Harvard, Vancouver, ISO, and other styles

25

Blundell, S. A. "Calculation of QED corrections in highly charged Zn-like ions." Canadian Journal of Physics 87, no. 1 (January 1, 2009): 55–65. http://dx.doi.org/10.1139/p08-065.

Full text

Abstract:

We report calculations of many-electron quantum electrodynamic (QED) effects for the 4s2 1S0–4s4p 1P1 transition in high-Z Zn-like ions with Z = 70, 74, 76, 79, 82, 83, 90, and 92. When combined with earlier relativistic many-body perturbation theory (RMBPT) calculations, good agreement is found with recent measurements, Trabert et al. (Phys. Rev. A, 70, 032506 (2004)) at the level of 1–2 experimental standard deviations. We discuss the additional QED and RMBPT calculations that it would be desirable to perform to confirm this level of agreement.PACS Nos.: 31.30.Jv, 32.30.Rj, 31.25.–v, 31.15.Ar

APA, Harvard, Vancouver, ISO, and other styles

26

Zhang, Chun Mei, Yan Sun, Chao Chen, Feng Wang, Bin Shao, and Bing Cong Gou. "Energy, fine structure, hyperfine structure, and transitions for the high-lying multi-excited 4Pe,o states of B-like ions." Canadian Journal of Physics 94, no. 5 (May 2016): 448–57. http://dx.doi.org/10.1139/cjp-2015-0609.

Full text

Abstract:

The energies of the high-lying multi-excited states 1s22s2pnl and 1s22p2nl 4Pe,o (n ≥ 2) for B-like C+, N2+, F4+, and Mg7+ ions are calculated using Rayleigh–Ritz variation method with multiconfiguration interaction, and the inclusion of mass polarization and relativistic corrections. The fine structure and hyperfine structure for these systems are investigated using first-order perturbation theory. The configuration structure of the high-lying multi-excited series is identified not only by energy, but also by its contribution to normalization of the angular spin components, and it is further tested by the addition of relativistic corrections and fine structure splittings. Transition wavelengths including the quantum electrodynamic effects and higher-order relativistic corrections are determined.

APA, Harvard, Vancouver, ISO, and other styles

27

Drake, G. WF, W. Nörtershäuser, and Z. C. Yan. "Isotope shifts and nuclear radius measurements for helium and lithium." Canadian Journal of Physics 83, no. 4 (April 1, 2005): 311–25. http://dx.doi.org/10.1139/p05-020.

Full text

Abstract:

It is now well established that accurate relative values of the rms nuclear charge radius for light atoms can be extracted from a comparison between high-precision theory and experiment for the isotope shift in atomic transition frequencies. Results are available for isotopes of helium and lithium. This paper reviews and updates the interpretation of earlier measurements for 3He relative to 4He, and 6Li relative to 7Li. New results are presented for the quantum electrodynamic recoil corrections. Recent measurements for the halo nucleus 6He, and the short-lived nuclei 8Li, and 9Li are discussed. The derived nuclear charge radii of 2.054(14), 2.30(4), and 2.24(4)~fm, respectively, are compared with the predictions of various nuclear structure models.PACS Nos.: 31.15.Pf, 31.30.Jv, and 32.10.Hq

APA, Harvard, Vancouver, ISO, and other styles

28

Yan, Zong-Chao, and G. W. F. Drake. "General methods for evaluating matrix elements of singular operators in two-electron systems." Canadian Journal of Physics 72, no. 11-12 (November 1, 1994): 822–44. http://dx.doi.org/10.1139/p94-109.

Full text

Abstract:

Due to the recent advances in both theory and experiment for the fine structure of two-electron atomic systems, it is necessary to include quantum electrodynamic (QED) effects through orders α6mc2, α7ln(Zα)mc2, and α7mc2, in order to match the experimental precision. These effects can be expressed in terms of a sum of singular operators. A general scheme is given for the evaluation of a wide range of matrix elements of high-order singular QED operators for two-electron atomic systems in Hylleraas coordinates. The scheme presented here can be applied to triplet states with arbitrary angular momentum. A number of useful expressions for the analytical evaluation of radial integrals are derived. An example is given in calculating the Douglas and Kroll terms, and the numerical values of the reduced matrix elements are presented for the 2 3PJ states of helium.

APA, Harvard, Vancouver, ISO, and other styles

29

Drake, GWF, and W. C. Martin. "Article." Canadian Journal of Physics 76, no. 9 (September 1, 1998): 679–98. http://dx.doi.org/10.1139/p98-044.

Full text

Abstract:

Ionization energies for several of the lower lying S- and P-states of helium are deduced from a combination of theory and a variety of high-precision measurements of transition energies. High-precision variational methods are reviewed and used to subtract the nonrelativistic energy and lowest order α2 au relativistic corrections from the ionization energies. The remaining quantum electrodynamic (QED) shift of order α3 au and higher is calculated in an extended KabirSalpeter formalism and compared with experiment. The comparison verifies the usefulness of the KabirSalpeter formalism for terms at least up to order α4 au, and it verifies an asymptotic 1/n3 scaling law for the two-electron corrections to the Bethe logarithm. The asymptotic scaling law is used to obtain improved semi-empirical estimates for the ionization energies of the higher lying 1sns 1S and 3S states up to n = 10. A revised comprehensive listing is given for the ionization energies of all states of helium up to n = 10 and angular momentum L = 7, together with quantum defect extrapolations for the S-states. PACS Nos.: 31.15.Pf, 31.30.Jv, and 32.10.Hq

APA, Harvard, Vancouver, ISO, and other styles

30

Gao, J., F. Shen, and J. G. Eden. "Polarization effects and the role of above-threshold ionization photoelectrons in high-order harmonic generation: comparison of experiment with quantum electrodynamic theory." Journal of Physics B: Atomic, Molecular and Optical Physics 32, no. 17 (August 17, 1999): 4153–61. http://dx.doi.org/10.1088/0953-4075/32/17/302.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Pinto, Fabrizio. "Gravitational Dispersion Forces and Gravity Quantization." Symmetry 13, no. 1 (December 29, 2020): 40. http://dx.doi.org/10.3390/sym13010040.

Full text

Abstract:

The parallel development of the theories of electrodynamical and gravitational dispersion forces reveals important differences. The former arose earlier than the formulation of quantum electrodynamics so that expressions for the unretarded, van der Waals forces were obtained by treating the field as classical. Even after the derivation of quantum electrodynamics, semiclassical considerations continued to play a critical role in the interpretation of the full results, including in the retarded regime. On the other hand, recent predictions about the existence of gravitational dispersion forces were obtained without any consideration that the gravitational field might be fundamentally classical. This is an interesting contrast, as several semiclassical theories of electrodynamical dispersion forces exist although the electromagnetic field is well known to be quantized, whereas no semiclassical theory of gravitational dispersion forces was ever developed although a full quantum theory of gravity is lacking. In the first part of this paper, we explore this evolutionary process from a historical point of view, stressing that the existence of a Casimir effect is insufficient to demonstrate that a field is quantized. In the second part of the paper, we show that the recently published results about gravitational dispersion forces can be obtained without quantizing the gravitational field. This is done first in the unretarded regime by means of Margenau’s treatment of multipole dispersion forces, also obtaining mixed potentials. These results are extended to the retarded regime by generalizing to the gravitational field the approach originally proposed by McLachlan. The paper closes with a discussion of experimental challenges and philosophical implications connected to gravitational dispersion forces.

APA, Harvard, Vancouver, ISO, and other styles

32

Labzowsky, L. N., G. Schedrin, D. Solovyev, and G. Plunien. "Nonresonant corrections and limits for the accuracy of the frequency measurements in modern hydrogen experiments." Canadian Journal of Physics 85, no. 5 (May 1, 2007): 585–95. http://dx.doi.org/10.1139/p07-014.

Full text

Abstract:

The theory of the nonresonant corrections, defining the limits of accuracy for the frequency measurements in resonance experiments, is generalized to the situation when the excitation of an atomic state is governed by one Hamiltonian Ĥin and the decay of the excited state is governed by another Hamiltonian Ĥout. The description developed here corresponds to the experimental conditions realized in most accurate modern resonance-frequency measurements of the 2s–1s transition in hydrogen. Two different variants of the theoretical description of the resonance experiments, referred to as "statistical" and "coherent" scenarios, are discussed. The criterion of how to define which scenario should be attributed to a particular resonance experiment is shown. The in and (or) out quantum electrodynamic formalism referring to different asymptotic Hamiltonians is applied. A value of 10–5 Hz, obtained for the accuracy limit in the 1s–2s experiment within the "coherent" scenario, is not so far from the accuracy already achieved experimentally (46 Hz). The accuracy limits for the Lyman-alpha frequency measurements for a "coherent" type of experiment are also obtained and shown to be comparable with recent experimental accuracy.PACS Nos.: 06.20.Jr, 31.10.+z, 32.30Bv

APA, Harvard, Vancouver, ISO, and other styles

33

Hartin, Anthony. "Strong field QED in lepton colliders and electron/laser interactions." International Journal of Modern Physics A 33, no. 13 (May 9, 2018): 1830011. http://dx.doi.org/10.1142/s0217751x18300119.

Full text

Abstract:

The studies of strong field particle physics processes in electron/laser interactions and lepton collider interaction points (IPs) are reviewed. These processes are defined by the high intensity of the electromagnetic fields involved and the need to take them into account as fully as possible. Thus, the main theoretical framework considered is the Furry interaction picture within intense field quantum field theory. In this framework, the influence of a background electromagnetic field in the Lagrangian is calculated nonperturbatively, involving exact solutions for quantized charged particles in the background field. These “dressed” particles go on to interact perturbatively with other particles, enabling the background field to play both macroscopic and microscopic roles. Macroscopically, the background field starts to polarize the vacuum, in effect rendering it a dispersive medium. Particles encountering this dispersive vacuum obtain a lifetime, either radiating or decaying into pair particles at a rate dependent on the intensity of the background field. In fact, the intensity of the background field enters into the coupling constant of the strong field quantum electrodynamic Lagrangian, influencing all particle processes. A number of new phenomena occur. Particles gain an intensity-dependent rest mass shift that accounts for their presence in the dispersive vacuum. Multi-photon events involving more than one external field photon occur at each vertex. Higher order processes which exchange a virtual strong field particle resonate via the lifetimes of the unstable strong field states. Two main arenas of strong field physics are reviewed; those occurring in relativistic electron interactions with intense laser beams, and those occurring in the beam–beam physics at the interaction point of colliders. This review outlines the theory, describes its significant novel phenomenology and details the experimental schema required to detect strong field effects and the simulation programs required to model them.

APA, Harvard, Vancouver, ISO, and other styles

34

Michael Köhler, J., Danja Kuhfuß, Phillip Witthöft, Martina Hentschel, and Andrea Knauer. "Single-Photon-Single-Electron Transition for Interpretation of Optical Spectra of Nonspherical Metal Nanoparticles in Aqueous Colloidal Solutions." Journal of Nanomaterials 2018 (August 30, 2018): 1–8. http://dx.doi.org/10.1155/2018/1781389.

Full text

Abstract:

Noble metal nanoparticles—especially shape anisotropic particles—have pronounced resonances in the optical spectrum. These sensitive absorption modes attract great interest in various fields of application. For nonspherical particles, no analytic description of the absorption spectra according to the commonly used Mie theory is possible. In this work, we present a semi-empirical approach for the explanation of the optical spectra of shape anisotropic particles such as silver nanoprisms and gold nanorods. We found an interpretation of the optical absorption spectra which is based on a single-photon-single-electron transition. This model is in a better agreement with the basic assumptions of quantum mechanics than the electrodynamic model of a localized surface plasmon excitation. Based on microfluidically obtained Ag nanoprisms and Au nanorods with very high ensemble homogeneities, dependencies between the geometrical properties of the shape anisotropic noble metal nanoparticles and the spectral position of the longitudinal absorption mode could be derived, which show that the assumption of a composed relative permittivity and the inclusion of the Rydberg constant is sufficient to describe the optical properties of the shape anisotropic particles. Within the scope of the measuring accuracy, the calculations furthermore lead to the value of the refractive index of the particle-surrounding medium.

APA, Harvard, Vancouver, ISO, and other styles

35

Cirilo-Lombardo, Diego Julio. "Non-Riemmanian geometry, force-free magnetospheres and the generalized Grad-Shafranov equation." International Journal of Geometric Methods in Modern Physics 16, no. 01 (January 2019): 1950013. http://dx.doi.org/10.1142/s0219887819500130.

Full text

Abstract:

The magnetosphere structure of a magnetar is considered in the context of a theory of gravity with dynamical torsion field beyond the standard General Relativity (GR). To this end, the axially symmetric version of the Grad-Shafranov equation (GSE) is obtained in this theoretical framework. The resulting GSE solution in the case of the magnetosphere corresponds to a stream function containing also a pseudoscalar part. This function solution under axisymmetry presents a complex character that (as in the quantum field theoretical case) could be associated with an axidilaton field. Magnetar–pulsar mechanism is suggested and the conjecture about the origin of the excess energy due the GSE describing the magnetosphere dynamics is claimed. We also show that two main parameters of the electrodynamic processes (as described in GR framework by Goldreich and Julian (GJ) [Astrophys. J. 157 (1969) 869]) are modified but the electron-positron pair rate [Formula: see text] remains invariant. The possible application of our generalized equation (defined in a non-Riemannian geometry) to astrophysical scenarios involving emission of energy by gravitational waves, as described in the context of GR in [S. Capozziello, M. De Laurentis, I. De Martino, M. Formisano and D. Vernieri, Astrophys. Space Sci. 333 (2011) 29–35], is briefly discussed.

APA, Harvard, Vancouver, ISO, and other styles

36

Rebhan, Anton, and Günther Turk. "Polarization effects in light-by-light scattering: Euler–Heisenberg versus Born–Infeld." International Journal of Modern Physics A 32, no. 10 (April 6, 2017): 1750053. http://dx.doi.org/10.1142/s0217751x17500531.

Full text

Abstract:

The angular dependence of the differential cross-section of unpolarized light-by-light scattering summed over final polarizations is the same in any low-energy effective theory of quantum electrodynamics and also in Born–Infeld electrodynamics. In this paper, we derive general expressions for polarization-dependent low-energy scattering amplitudes, including a hypothetical parity-violating situation. These are evaluated for quantum electrodynamics with charged scalar or spinor particles, which give strikingly different polarization effects. Ordinary quantum electrodynamics is found to exhibit rather intricate polarization patterns for linear polarizations, whereas supersymmetric quantum electrodynamics and Born–Infeld electrodynamics give particularly simple forms.

APA, Harvard, Vancouver, ISO, and other styles

37

Treumann, Rudolf A., Wolfgang Baumjohann, and Yasuhito Narita. "Inverse scattering problem in turbulent magnetic fluctuations." Annales Geophysicae 34, no. 8 (August 16, 2016): 673–89. http://dx.doi.org/10.5194/angeo-34-673-2016.

Full text

Abstract:

Abstract. We apply a particular form of the inverse scattering theory to turbulent magnetic fluctuations in a plasma. In the present note we develop the theory, formulate the magnetic fluctuation problem in terms of its electrodynamic turbulent response function, and reduce it to the solution of a special form of the famous Gelfand–Levitan–Marchenko equation of quantum mechanical scattering theory. The last of these applies to transmission and reflection in an active medium. The theory of turbulent magnetic fluctuations does not refer to such quantities. It requires a somewhat different formulation. We reduce the theory to the measurement of the low-frequency electromagnetic fluctuation spectrum, which is not the turbulent spectral energy density. The inverse theory in this form enables obtaining information about the turbulent response function of the medium. The dynamic causes of the electromagnetic fluctuations are implicit to it. Thus, it is of vital interest in low-frequency magnetic turbulence. The theory is developed until presentation of the equations in applicable form to observations of turbulent electromagnetic fluctuations as input from measurements. Solution of the final integral equation should be done by standard numerical methods based on iteration. We point to the possibility of treating power law fluctuation spectra as an example. Formulation of the problem to include observations of spectral power densities in turbulence is not attempted. This leads to severe mathematical problems and requires a reformulation of inverse scattering theory. One particular aspect of the present inverse theory of turbulent fluctuations is that its structure naturally leads to spatial information which is obtained from the temporal information that is inherent to the observation of time series. The Taylor assumption is not needed here. This is a consequence of Maxwell's equations, which couple space and time evolution. The inversion procedure takes advantage of a particular mapping from time to space domains. Though the theory is developed for homogeneous stationary non-flowing media, its extension to include flows, anisotropy, non-stationarity, and the presence of spectral lines, i.e. plasma eigenmodes like those present in the foreshock or the magnetosheath, is obvious.

APA, Harvard, Vancouver, ISO, and other styles

38

Biava, P. M., F. Burigana, R. Germano, P. Kurian, C. Verzegnassi, and G. Vitiello. "Stem Cell Differentiation Stage Factors and their Role in Triggering Symmetry Breaking Processes during Cancer Development: A Quantum Field Theory Model for Reprogramming Cancer Cells to Healthy Phenotypes." Current Medicinal Chemistry 26, no. 6 (May 13, 2019): 988–1001. http://dx.doi.org/10.2174/0929867324666170920142609.

Full text

Abstract:

A long history of research has pursued the use of embryonic factors isolated during cell differentiation processes for the express purpose of transforming cancer cells back to healthy phenotypes. Recent results have clarified that the substances present at different stages of cell differentiation—which we call stem cell differentiation stage factors (SCDSFs)—are proteins with low molecular weight and nucleic acids that regulate genomic expression. The present review summarizes how these substances, taken at different stages of cellular maturation, are able to retard proliferation of many human tumor cell lines and thereby reprogram cancer cells to healthy phenotypes. The model presented here is a quantum field theory (QFT) model in which SCDSFs are able to trigger symmetry breaking processes during cancer development. These symmetry breaking processes, which lie at the root of many phenomena in elementary particle physics and condensed matter physics, govern the phase transitions of totipotent cells to higher degrees of diversity and order, resulting in cell differentiation. In cancers, which share many genomic and metabolic similarities with embryonic stem cells, stimulated redifferentiation often signifies the phenotypic reversion back to health and nonproliferation. In addition to acting on key components of the cellular cycle, SCDSFs are able to reprogram cancer cells by delicately influencing the cancer microenvironment, modulating the electrochemistry and thus the collective electrodynamic behaviors between dipole networks in biomacromolecules and the interstitial water field. Coherent effects in biological water, which are derived from a dissipative QFT framework, may offer new diagnostic and therapeutic targets at a systemic level, before tumor instantiation occurs in specific tissues or organs. Thus, by including the environment as an essential component of our model, we may push the prevailing paradigm of mutation-driven oncogenesis toward a closer description of reality.

APA, Harvard, Vancouver, ISO, and other styles

39

Stumpf, H., B. Fauser, and W. Pfister. "Composite Particle Theory in Quantum Electrodynamics." Zeitschrift für Naturforschung A 48, no. 7 (July 1, 1993): 765–76. http://dx.doi.org/10.1515/zna-1993-0705.

Full text

Abstract:

Abstract Without use of pathintegral formalism a composite particle effective dynamics is developed for spinor quantum electrodynamics. By algebraic evaluation of spinor quantum electrodynamics in Coulomb gauge a corresponding functional equation is derived. The commutation rules for the transversal electromagnetic field can be deduced as a consequence of this formalism. By application of weak mapping theorems the QED functional equation can be mapped onto a functional equation for composite particles with mutual interaction and interaction with the electromagnetic field. The formalism is demonstrated for positronium states. The incorporation of renormalization into this scheme is verified.

APA, Harvard, Vancouver, ISO, and other styles

40

Ganai, Prince A., Owais Ahmad, Javier Perez Tobia, Alexander Fennell, and Vedaant Vyas. "Lorentz symmetry breaking in supersymmetric quantum electrodynamics." International Journal of Geometric Methods in Modern Physics 17, no. 03 (March 2020): 2050038. http://dx.doi.org/10.1142/s0219887820500383.

Full text

Abstract:

Lorentz symmetry is one of the fundamental symmetries of nature; however, it can be broken by several proposals such as quantum gravity effects, low energy approximations in string theory and dark matter. In this paper, Lorentz symmetry is broken in supersymmetric quantum electrodynamics using aether superspace formalism without breaking any supersymmetry. To break the Lorentz symmetry in three-dimensional quantum electrodynamics, we must use the [Formula: see text] aether superspace. A new constant vector field is introduced and used to deform the deformed generator of supersymmetry. This formalism is required to fix the unphysical degrees of freedom that arise from the quantum gauge transformation required to quantize this theory. By using Yokoyama’s gaugeon formalism, it is possible to study these gaugeon transformations. As a result of the quantum gauge transformation, the supersymmetric algebra gets modified and the theory is invariant under BRST symmetry. These results could aid in the construction of the Gravity’s Rainbow theory and in the study of superconformal field theory. Furthermore, it is demonstrated that different gauges in this deformed supersymmetric quantum electrodynamics can be related to each other using the gaugeon formalism.

APA, Harvard, Vancouver, ISO, and other styles

41

Berrondo, M., and R. Jáuregui. "Minimal theory of quantum electrodynamics." Physical Review D 33, no. 2 (January 15, 1986): 455–63. http://dx.doi.org/10.1103/physrevd.33.455.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Wilson, James H. "The quantum electrodynamics physical (QED-P) theory to complement quantum electrodynamics (QED)." Physics Essays 34, no. 1 (March 21, 2021): 17–27. http://dx.doi.org/10.4006/0836-1398-34.1.17.

Full text

Abstract:

The electronic and muonic hydrogen energy levels are calculated very accurately [M. L. Eides, H. Grotch, and V. Shelyuto, Phys. Rep. 342, 63 (2001)] in Quantum Electrodynamics (QED) by coupling the Dirac Equation four vector c(α, I) current covariantly with the external electromagnetic (EM) field four vector in QED’s Interactive Representation. While QED has been extraordinarily successful computationally, it presents no physical description of the electron, or other charged leptons. The QED-Physical (QED-P) theory presented in this paper is equivalent to QED in that it is based only on the four-current c(α, I) that is the reason that QED is so accurate computationally. However, QED-P describes the electron geometrically through the internal time/coordinate operators derived directly from c(α, I) with no assumptions. QED-P’s internal coordinate operators define an electron Center of Charge (CoC) point vibrating rapidly in space and time in its unique vacuum, creating the current that produces the electron’s magnetic moment and spin, and eliminating the need for “intrinsic” properties. QED-P also cuts off the photon propagator in a natural way so that the electron self-energy is finite and ad hoc renormalization procedures are not necessary. The c α-Non Exclusion Principle states that, if QED accepts c(α, I) as the electron current operator because of the very accurate hydrogen energy levels calculated, then one must also accept the QED-P electron internal spatial and time coordinate operators (ISaTCO) derived directly from c(α, I) without any other assumptions. QED-P shows the electron to be in both spin states simultaneously, and it is the external EM field that forces the electron’s spin state to be measured up or down. QED-P describes the bizarre, and very different, situation illustrated in Fig. 1 when the electron and muon are located “inside” the spatially extended proton with their CoCs orbiting the proton at the speed of light in S energy states of hydrogen, shedding some insight into the proton radius puzzle. The electron only appears to be a point particle with intrinsic properties when observed/measured from the far field. The Dirac‐Maxwell‐Wilson Equations are derived directly from the electron ISaTCO, and its EM fields “look” like they are from a point particle in far field scattering experiments in the same way the electric field from a sphere with evenly distributed charge “e” looks like a point charge with the same charge in the far field (Gauss Law). A physical basis for Quantum Entanglement is derived that can be measured experimentally.

APA, Harvard, Vancouver, ISO, and other styles

43

AKHMETELI, ANDREY. "IS NO DRAMA QUANTUM THEORY POSSIBLE?" International Journal of Quantum Information 09, supp01 (January 2011): 17–26. http://dx.doi.org/10.1142/s0219749911006909.

Full text

Abstract:

The matter field can be naturally eliminated from the equations of the Klein-Gordon-Maxwell electrodynamics in the unitary gauge. The resulting equations describe independent dynamics of the electromagnetic field: if components of the 4-potential of the electromagnetic field and their first derivatives with respect to time are known in the entire space at some time point, the values of their second derivatives with respect to time can be calculated for the same time point, so the Cauchy problem can be posed, and integration yields the 4-potential in the entire space-time. This surprising result both permits mathematical simplification and can be useful for interpretation of quantum theory. For example, in the Bohm interpretation, the electromagnetic field can replace the wave function as the guiding field. Independent of the interpretation, quantum phenomena can be described in terms of electromagnetic field only. For the system of nonlinear partial differential equations of the Klein-Gordon-Maxwell electrodynamics, a generalized Carleman linearization procedure generates a system of linear equations in the Hilbert space, which looks like a second-quantized theory and is equivalent to the original nonlinear system on the set of solutions of the latter. Similar, but less general results are obtained for the Dirac-Maxwell electrodynamics.

APA, Harvard, Vancouver, ISO, and other styles

44

DEMARCO, G., C. FOSCO, and R. C. TRINCHERO. "CONSISTENT CHIRAL QUANTUM ELECTRODYNAMICS." Modern Physics Letters A 06, no. 14 (May 10, 1991): 1299–304. http://dx.doi.org/10.1142/s0217732391001391.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Milton, Kimball A., E. K. Abalo, Prachi Parashar, Nima Pourtolami, and J. Wagner. "PT -symmetric quantum electrodynamics and unitarity." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 371, no. 1989 (April 28, 2013): 20120057. http://dx.doi.org/10.1098/rsta.2012.0057.

Full text

Abstract:

More than 15 years ago, a new approach to quantum mechanics was suggested, in which Hermiticity of the Hamiltonian was to be replaced by invariance under a discrete symmetry, the product of parity and time-reversal symmetry, . It was shown that, if is unbroken, energies were, in fact, positive, and unitarity was satisfied. Since quantum mechanics is quantum field theory in one dimension—time—it was natural to extend this idea to higher-dimensional field theory, and in fact an apparently viable version of -invariant quantum electrodynamics (QED) was proposed. However, it has proved difficult to establish that the unitarity of the scattering matrix, for example, the Källén spectral representation for the photon propagator, can be maintained in this theory. This has led to questions of whether, in fact, even quantum mechanical systems are consistent with probability conservation when Green’s functions are examined, since the latter have to possess physical requirements of analyticity. The status of QED will be reviewed in this paper, as well as the general issue of unitarity.

APA, Harvard, Vancouver, ISO, and other styles

46

Acharya, R., and P. Narayana Swamy. "No Eigenvalue in Finite Quantum Electrodynamics." International Journal of Modern Physics A 12, no. 21 (August 20, 1997): 3799–809. http://dx.doi.org/10.1142/s0217751x97001961.

Full text

Abstract:

We re-examine Quantum Electrodynamics (QED) with massless electron as a finite quantum field theory as advocated by Gell-Mann–Low, Baker–Johnson, Adler, Jackiw and others. We analyze the Dyson–Schwinger equation satisfied by the massless electron in finite QED and conclude that the theory admits no nontrivial eigenvalue for the fine structure constant.

APA, Harvard, Vancouver, ISO, and other styles

47

Zhuang, P., and U. Heinz. "Relativistic Quantum Transport Theory for Electrodynamics." Annals of Physics 245, no. 2 (February 1996): 311–38. http://dx.doi.org/10.1006/aphy.1996.0011.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

RECAMI, ERASMO, VLADISLAV S. OLKHOVSKY, and SERGEI P. MAYDANYUK. "ON NON-SELF-ADJOINT OPERATORS FOR OBSERVABLES IN QUANTUM MECHANICS AND QUANTUM FIELD THEORY." International Journal of Modern Physics A 25, no. 09 (April 10, 2010): 1785–818. http://dx.doi.org/10.1142/s0217751x10048007.

Full text

Abstract:

The aim of this paper is to show the possible significance, and usefulness, of various non-self-adjoint operators for suitable Observables in nonrelativistic and relativistic quantum mechanics, and in quantum electrodynamics. More specifically, this work deals with: (i) the maximal Hermitian (but not self-adjoint) time operator in nonrelativistic quantum mechanics and in quantum electrodynamics; (ii) the problem of the four-position and four-momentum operators, each one with its Hermitian and anti-Hermitian parts, for relativistic spin-zero particles. Afterwards, other physically important applications of non-self-adjoint (and even non-Hermitian) operators are discussed: in particular, (iii) we reanalyze in detail the interesting possibility of associating quasi-Hermitian Hamiltonians with (decaying) unstable states in nuclear physics. Finally, we briefly mention the cases of quantum dissipation, as well as of the nuclear optical potential.

APA, Harvard, Vancouver, ISO, and other styles

49

Veklenko, Boris A. "Energy, Information, and Superluminal Speed in Quantum Electrodynamics." Light & Engineering, no. 04-2020 (August 2020): 27–33. http://dx.doi.org/10.33383/2019-097.

Full text

Abstract:

Without using the perturbation theory, the article demonstrates a possibility of superluminal information-carrying signals in standard quantum electrodynamics using the example of scattering of quantum electromagnetic field by an excited atom.

APA, Harvard, Vancouver, ISO, and other styles

50

Costa, A. A. da. "Pulsar Geometrodynamics: Relativistic Radiative Plasma Theory and its Associated Quantum Phenomena." Symposium - International Astronomical Union 195 (2000): 385–86. http://dx.doi.org/10.1017/s007418090016320x.

Full text

Abstract:

Plasma motion in pulsar magnetospheres is quasi-classical due to curvature radiation of highly energetic gamma-ray photons, implying an extension to the kinetic theory of plasmas. But with high energies involved, other quantum radiative processes become important in the context of vacuum (quantum) electrodynamics.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Quantum electrodynamic theory'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles