scholarly journals QED Response of the Vacuum

Physics ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 14-21 ◽  
Author(s):  
Gerd Leuchs ◽  
Margaret Hawton ◽  
Luis L. Sánchez-Soto
Keyword(s):  
Electromagnetic Field ◽  
Quantum Electrodynamics ◽  
Displacement Vector ◽  
Electric Displacement ◽  
Structure Constant ◽  
Universal Constant ◽  
Field Vector ◽  
Fine Structure Constant ◽  
Source Current ◽  
New Perspective

We present a new perspective on the link between quantum electrodynamics (QED) and Maxwell’s equations. We demonstrate that the interpretation of the electric displacement vector D = ε 0 E , where E is the electric field vector and ε 0 is the permittivity of the vacuum, as vacuum polarization is consistent with QED. A free electromagnetic field polarizes the vacuum, but the polarization and magnetization currents cancel giving zero source current. The speed of light is a universal constant, while the fine structure constant, which couples the electromagnetic field to matter runs, as it should.

Direct Measurement of Excitation and Growth of Large Amplitude Cyclotron Waves by Reflected Ion Beams in Front of Shock

2020 ◽  
Author(s):  
Jiansen He ◽  
Chuanpeng Hou ◽  
Xingyu Zhu ◽  
Qiaowen Luo ◽  
Daniel Verscharen ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Electromagnetic Field ◽  
Phase Space ◽  
Large Amplitude ◽  
Particle Interaction ◽  
Field Vector ◽  
Ion Beams ◽  
Magnetic Field Vector ◽  
Wave Particle Interaction

<p>Wave-particle interaction plays a critical role in producing the newborn waves/turbulence in the foreshock region in front of supercritical shock, which is prevalent in the heliosphere. It has been a long-lasting goal to catch and witness the excitation and growth of waves/turbulence by identifying the ongoing process of wave-particle interaction. This goal cannot be fulfilled until the arrival of the MMS’s era, during which we can simultaneously measure the electromagnetic fields and particle phase space densities with the unprecedented data quality. By surveying the data of burst mode, we are lucky to find some good examples illustrating the clear signals of wave activities in front of the shock. The active waves are diagnosed to be right-handed cyclotron waves, being highly circularly polarized and rotating right-handed about the background magnetic field vector. The waves are large amplitude with dB being greatly dominant over B0, or in other words, almost the whole magnetic field vector is involved in the circular rotation. Furthermore, we investigate the growth evolution of the large-amplitude cyclotron waves by calculating the spectrum of dJ.dE and its ratio to the electromagnetic energy spectrum. As far as we know, it is the first time to provide the spectrum of growth rate from in-situ measurements. Interestingly, we find that the contribution to the growth rate spectrum mainly comes from dJ<sub>e,perp</sub>·dE<sub>perp</sub> rather than dJ<sub>e,para</sub>·dE<sub>para</sub> or d<strong>J</strong><sub>i</sub>·d<strong>E</strong>. Although the eigen mode to couple the oscillating electromagnetic field is the electron bulk oscillation, the ultimate free energy to make the eigen mode unstable comes from the ion beams, which are reflected from the shock. The dynamics of 3D phase space densities for both ion and electron species are also studied in detail together with the fluctuating electromagnetic field, demonstrating the ongoing energy conversion during the wave-particle process.</p><p> </p>

scholarly journals Two-Dimensional DOA Estimation for Monostatic MIMO Radar with Electromagnetic Vector Received Sensors

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Guimei Zheng ◽  
Jun Tang
Keyword(s):  
Electromagnetic Field ◽  
Estimation Method ◽  
Estimation Algorithm ◽  
Doa Estimation ◽  
Field Vector ◽  
Cross Product ◽  
Mimo Radar ◽  
Two Dimensional ◽  
Array Configuration ◽  
2D Doa Estimation

We study two-dimensional direction of arrival (2D-DOA) estimation problem of monostatic MIMO radar with the receiving array which consists of electromagnetic vector sensors (EMVSs). The proposed angle estimation algorithm can be applied to the arbitrary and unknown array configuration, which can be summarized as follows. Firstly, EMVSs in the receiver of a monostatic MIMO radar are used to measure all six electromagnetic-field components of an incident wavefield. The vector sensor array with the six unknown electromagnetic-field components is divided into six spatially identical subarrays. Secondly, ESPRIT is utilized to estimate the rotational invariant factors (RIFs). Parts of the RIFs are picked up to restore the source’s electromagnetic-field vector. Last, a vector cross product operation is performed between electric field and magnetic field to obtain the Pointing vector, which can offer the 2D-DOA estimation. Prior knowledge of array elements’ positions and angle searching procedure are not necessary for the proposed 2D-DOA estimation method. Simulation results prove the validity of the proposed method.

CLOSED ANALYTIC FORM FOR EVALUATION OF RELATIVISTIC BOUND-UNBOUND AND UNBOUND-UNBOUND TRANSITION MATRIX ELEMENTS OF HYDROGENIC ATOMS

2008 ◽  
Vol 22 (29) ◽  
pp. 5095-5102
Author(s):  
A. V. SOLDATOV ◽  
J. SEKE ◽  
G. ADAM ◽  
M. POLAK
Keyword(s):  
Electromagnetic Field ◽  
Plane Wave ◽  
Vector Potential ◽  
Transition Matrix ◽  
Analytic Form ◽  
Field Vector ◽  
Matrix Elements ◽  
Plane Wave Expansion ◽  
Transition Matrix Elements ◽  
Closed Analytic Form

A closed analytic form for relativistic bound-unbound and unbound-unbound transition matrix elements of hydrogenic atoms by using the plane-wave expansion for the electromagnetic-field vector potential is derived. By applying the obtained formulae, these transition matrix elements can be evaluated analytically and numerically.

scholarly journals Psychophysical interactions with photon polarization: Two exploratory studies

2019 ◽  
Author(s):  
Dean Radin ◽  
Loren Carpenter
Keyword(s):  
Electromagnetic Field ◽  
Light Intensity ◽  
Electric Field ◽  
Laser Beam ◽  
Field Vector ◽  
Illumination Intensity ◽  
Focused Attention ◽  
Electric Field Vector ◽  
Photon Polarization

The present study explored possible psychophysical interactions between focused mental intention and the electromagnetic field vector, i.e., polarization. To detect the hypothesized effect, a laser beam was passed through horizontal and vertical polarizers. Participants were asked to focus their attention on the beam between the two polarizers while holding the intention for the beam’s polarization to rotate. If the photons’ electric field vector was affected, then the illumination intensity of the beam exiting the second polarizer should increase. Two exploratory experiments both showed results contrary to the hypothesis, with illumination decreasing during periods when intention was focused toward the beam as compared to periods where attention was withdrawn. Reanalysis of data from previously published experiments, also involving mental influence of beams of light, but designed for different purposes and originally analyzed in other ways, also showed a reduction in light intensity during periods of focused attention. These studies suggest that psychophysical interactions with light appears to result in scattering or absorbing photons. Further research is warranted to confirm these results.

EVALUATION OF RELATIVISTIC TRANSITION MATRIX ELEMENTS OF HYDROGENIC ATOMS USING PLANE WAVE EXPANSION

2007 ◽  
Vol 21 (22) ◽  
pp. 3825-3840 ◽  
Author(s):  
A. V. SOLDATOV ◽  
J. SEKE ◽  
G. ADAM
Keyword(s):  
Electromagnetic Field ◽  
Plane Wave ◽  
Vector Potential ◽  
Transition Matrix ◽  
Field Vector ◽  
Matrix Elements ◽  
Plane Wave Expansion ◽  
Wave Expansion ◽  
Transition Matrix Elements ◽  
First Time

For the first time to our knowledge, a general, explicit formula for exact transition matrix elements in relativistic hydrogenic atoms is derived, by using the plane-wave expansion for the electromagnetic-field vector potential. By applying the obtained formula, discrete-discrete and discrete-continuous matrix elements are evaluated analytically and numerically.

scholarly journals Quantized Field of Single Photons

2020 ◽  
Author(s):  
Constantin Meis
Keyword(s):  
Electromagnetic Field ◽  
Vector Potential ◽  
Single Photon ◽  
Physical Property ◽  
Massless Particle ◽  
Field Vector ◽  
Single Photons ◽  
Quantum Vacuum ◽  
Real Component ◽  
Particle Nature

We present theoretical developments expressing the physical characteristics of a single photon in conformity with the experimental evidence. The quantization of the electromagnetic field vector potential amplitude is enhanced to a free of cavity photon state. Coupling the Schrödinger equation with the relativistic massless particle Hamiltonian to a symmetrical vector potential relation, we establish the vector potential - energy equation for the photon expressing the simultaneous wave-particle nature of a single photon, an intrinsic physical property. It is shown that the vector potential can be naturally considered as a real wave function for the photon entailing a coherent localization probability. We deduce directly the electric and magnetic field amplitudes of the cavity-free single photon, which are revealed to be proportional to the square of the angular frequency. The zero-energy electromagnetic field ground state (EFGS), a quantum vacuum real component, issues naturally from Maxwell’s equations and the vector potential quantization procedure. The relation of the quantized amplitude of the photon vector potential to the electron-positron charge results directly showing the physical relationship between photons and electrons-positrons that might be at the origin of their mutual transformations. It becomes obvious that photons, as well as electrons-positrons, are issued from the same quantum vacuum field.

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