Generalized Gravi—Electromagnetism

A self consistant and manifestly covariant theory for the dynamics of four charges (masses) (namely electric, magnetic, gravitational, Heavisidian) has been developed in simple, compact and consistent manner. Starting with an invariant Lagrangian density and its quaternionic representation, we have obtained the consistent field equation for the dynamics of four charges. It has been shown that the present reformulation reproduces the dynamics of individual charges (masses) in the absence of other charge (masses) as well as the generalized theory of dyons (gravito-dyons) in the absence gravito-dyons (dyons).     

Unexpected behavior of the near-threshold double-photoionization cross section of beryllium

The threshold region of the double-photoionization cross section of atomic beryllium was investigated using monochromatized synchrotron radiation. The photon energy dependence of the double-photoionization cross section can be described by the Wannier power law up to 1.7 eV above threshold. However, we unexpectedly find oscillations in the cross section, which are in excellent agreement with a modulated threshold law based on the Coulomb-dipole theory [Phys. Rev. Lett. 49, 365 (1982)]]. This new finding casts some doubts on the general applicability of the Wannier power law.     

The state of an atomic-molecular system near the stability threshold

The state of an atomic-molecular system near its stability threshold with regard to the detachment of one of the particles is studied. The decay of the system upon a decrease in the charge of a binding particle, as well upon an increasasymmetry of masses of like-charged particles, is considered. A special variational principle that allows one to directly calculate the threshold state of the system without repeatedly calculating its energy for different values of masses and charges of particles is used. With the motion of all particles fully taken into account, the threshold states of two-electron atoms with different nuclear charges and of atomic-molecular systems corresponding to the attachment of a positron of variable mass to a neutral atom are calculated. On the basis of calculation of quantum-mechanical expectation values of the kinetic energy of particles and the potential energy of their interaction, the rearrangement of the wave function upon passage of the system through the decay threshold is examined. The threshold characteristics of a purely adiabatic system containing infinitely heavy particles are considered separately.     

Wannier-based definition of layer polarizations in perovskite superlattices

In insulators, the method of Marzari and Vanderbilt [Phys. Rev. B 56, 12 847 (1997)] can be used to generate maximally localized Wannier functions whose centers are related to the electronic polarization. In the case of layered insulators, this approach can be adapted to provide a natural definition of the local polarization associated with each layer, based on the locations of the nuclear charges and one-dimensional Wannier centers comprising each layer. Here, we use this approach to compute and analyze layer polarizations of ferroelectric perovskite superlattices, including changes in layer polarizations induced by sublattice displacements (i.e., layer-decomposed Born effective charges) and local symmetry breaking at the interfaces. The method provides a powerful tool for analyzing the polarization-related properties of complex layered oxide systems.     

Orbital magnetization in periodic insulators

Working in the Wannier representation, we derive an expression for the orbital magnetization of a periodic insulator. The magnetization is shown to be comprised of two contributions, an obvious one associated with the internal circulation of bulklike Wannier functions in the interior, and an unexpected one arising from net currents carried by Wannier functions near the surface. Each contribution can be expressed as a bulk property in terms of Bloch functions in a gauge-invariant way. Our expression is verified by comparing numerical tight-binding calculations for finite and periodic samples.     

Resonance formation in few (3) body Coulomb systems

The standard physical picture of resonance formation breaks down for three-body Coulomb systems close to the threshold for total fragmentation. Near this threshold the complex as a whole performs collective motions localised essentially along potential energy surface ridges. Above threshold these motions are nonperiodic and describe total fragmentation, below threshold unstable periodic motions lead to new resonances. A semiclassical theory which describes these phenomena for two-electron atoms in excellent agreement with experiments is generalised to the ppp system.     

Threshold Fragmentation under Dipole Forces

The threshold law for N-body fragmentation under dipole forces is formulated. It emerges from the energy dependence of the normalization of the correlated continuum wave function for N fragments. It is shown that the dipole threshold law plays a key role in understanding all threshold fragmentation phenomena since it links the classical threshold law for long-range Coulomb interactions to the statistical law for short-range interactions. Furthermore, a tunnelling mechanism is identified as the common feature which occurs for all three classes of interactions, short-range, dipole and Coulomb.     

Quenching of exciton diamagnetic shifts in polar,layered materials

A theory for Wannier excitons in a magnetic field or arbitrary strength, including both anisotropy and exciton-phonon coupling, is presented. Both the anisotropy and the exciton-phonon coupling are shown to considerably quench the shifts of the energy levels in the magnetic field. Results are presented for PbI₂ and compared with recent experimental data.     

Charging energy and stability of charged metallic particles

The stability of a charged metallic particle is investigated within the classical theory. The minimal number of atoms for which a charged spherical particle is stable against the spheroidal deformation, which relaxes the energy cost due to the Coulomb repulsion between extra charges, is derived. It is suggested that, for negatively charged particles, an extra electron virtually bound to particle is emitted before the fragmentation due to the Coulomb repulsion between extra charges will occur.     

Raman scattering of light by 2LO-phonons

A theory of resonance Raman scattering of light by 2LO-phonons in semiconductor crystals is presented. Wannier excitons are considered as intermediate states. Analytic expressions are obtained that take into account contributions from different chains of intermediate states. The scattering cross section is shown to be weakly dependent on the wave vector imparted to the phonon system. The theoretical model permits the calculation of the scattering cross section for the energy of the exciting radiation photon below the level of exciton resonances.     

Initial state dependence in multielectron threshold ionization of atoms

It is shown that the geometry of multielectron threshold ionization in atoms depends on the initial configuration of bound electrons. The reason for this behavior is found in the stability properties of the classical fixed point of the equations of motion for multiple threshold fragmentation. Specifically for three-electron breakup, apart from the symmetric triangular configuration also a breakup of lower symmetry in the form of a T shape can occur, as we demonstrate by calculating triple photoionization for the lithium ground and first excited states. We predict the electron breakup geometry for threshold fragmentation experiments.     

All possible generators of supersymmetries of the S-matrix

A generator of a symmetry or supersymmetry of the S-matrix has to have three simple properties (see sect. 2). Starting from these properties one can give a complete analysis of the possible structure of the pseudo Lie algebra of these generators. In a theory with non-vanishing masses one finds that the only extension of previously known relations is the possible appearance of “central charges” as anticommutators of Fermi charges. In the massless case (disregarding infrared problems and symmetry breaking) the Fermi charges may generate the conformal group together with a unitary internal symmetry group.     

Charge, Geometry, and Effective Mass

Charge, like mass in Newtonian mechanics, is an irreducible element of electromagnetic theory that must be introduced ab initio. Its origin is not properly a part of the theory. Fields are then defined in terms of forces on either masses—in the case of Newtonian mechanics, or charges in the case of electromagnetism. General Relativity changed our way of thinking about the gravitational field by replacing the concept of a force field with the curvature of space-time. Mass, however, remained an irreducible element. It is shown here that the Reissner-Nordström solution to the Einstein field equations tells us that charge, like mass, has a unique space-time signature.     

Oscillations in the double-photoionization cross section of Li near threshold

The threshold region of the double-photoionization cross section of lithium was investigated using monochromatized synchrotron radiation and ion time-of-flight spectrometry. While the overall energy dependence can be described by the Wannier power law, we found oscillations in the cross section which are in good agreement with a modulated threshold law as proposed by Temkin [Phys. Rev. Lett. 49, 365 (1982)]]. This behavior may be due to the unequal binding energies of the electrons involved in the double-photoionization process.     

CPT,Lorentz invariance,mass differences,and charge non-conservation

A non-local field theory that breaks discrete symmetries, including C, P, CP, and CPT, but preserves Lorentz symmetry, is presented. We demonstrate that at one-loop level the masses for particle and antiparticle remain equal due to Lorentz symmetry only. An inequality of masses implies breaking of the Lorentz invariance and non-conservation of the usually conserved charges.     

A direct test of the quark-parton model in e+e−-annihilation

Opposite side mesons in e⁺e^?-annihilation are expected to show characteristic correlation patterns in the quark-parton model. In the limit where the momentum fraction carried by the meson approaches one, a suitably defined correlation is independent of the fragmentation functions and becomes a simple number reflecting the charges of the quarks. The change in the correlation measure in crossing a new quark threshold provides a measurement of the charge of the new quark, independent of “color”.     

On a new general theory of earthquakes

Summary Some phenomena have been observed a very brief time before an intense earthquake: variations of the terrestrial magnetic and electric fields, rumble and also often animal nervousness. In order to give a sole explanation of all these phenomena, a general theory of the earthquake has been built, based on separation of the electric charges when the internal terrestrial masses are subject to strong compressive stress for piezoelectric effect. If the separation of the electric charges takes place on very large masses, intense electric fields are produced so to generate strong electric potential differences. If these differences are higher that the dielectric rigidity of the materials, a strong disruptive discharge can occur between the terrestrial masses. The destruction of some masses allows other masses to move generating intense seismic waves. The discharge produces the rumble and electromagnetic waves with frequencies depending on the dimensions on the focus. The tables show that the calculated frequencies (ultra-audible vibrations) are 35, 23, 17, 14, 12 kHz. (This abstract was published on Bulletin of S.I.F. on 10 September 1982, N. 127).     

近阈值下He原子的双电子电离实验中出射电子研究

利用适用于低能电子入射的反应显微成像谱仪，对电子入射He原子近阈值下的双电离过程进行了研究，实验测量了反应后3个粒子的全部动量，获得了出射电子间的关联信息.主要介绍近阈值下的双电离实验装置及实验技术，集中分析反应后出射电子的动量能量关系，对描述近阈值双电离的Wannier理论进行了检验，发现在入射电子能量为106eV时，实验结果具有Wannier理论预言的性质.