Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Four-current density

In the relativistic version of DFT, the ground state energy of the system is a unique functional of the fermion four-current density, / (/-) ... [Pg.138]

In this equation, A, is a given external four-potential and J (x) is the four-current density. As the treatment is for stationary states, the external four-potential and the fermion four-current are independent of time. [Pg.138]

The energy (3.32) is, via the (rather involved) dependence of the RKS-orbitals on the four current density, a functional of this quantity,... [Pg.22]

In Section V it will be shown that the quaternion structure of the fields that correspond to the electromagnetic field tensor and its current density source, implies a very important consequence for electromagnetism. It is that the local limit of the time component of the four-current density yields a derived normalization. The latter is the condition that was imposed (originally by Max Bom) to interpret quantum mechanics as a probability calculus. Here, it is a derived result that is an asymptotic feature (in the flat spacetime limit) of a field theory that may not generally be interpreted in terms of probabilities. Thus, the derivation of the electromagnetic field equations in general relativity reveals, as a bonus, a natural normalization condition that is conventionally imposed in quantum mechanics. [Pg.680]

My investigation proceeded along the following lines [12]. The conventional coupling of an external electromagnetic potential field A to an electrical four-current density of matter is in terms of the scalar interaction Lagrangian... [Pg.681]

We see here that the real and imaginary parts of the complex invariant I correspond to the two invariants of the standard form of electromagnetic theory, namely, the scalar and the pseudoscalar terms. They appear together here in a single complex function because of the reflection-nonsymmetric feature of this theory. The invariant h corresponds to the real-valued modulus of the four-current density of the standard theory. [Pg.689]

In this expression for the electromagnetic field intensity tensor, Q is a constant of proportionality with the dimension of charge, inserted on both sides of Eq. (48) (negative). The four-current density is... [Pg.700]

Integration of the local limit of Eq. (50) for the four-current density source of Maxwell s equations, together with the boundary condition that the... [Pg.702]

Thus, the four-current density jy of this expression of the Maxwell theory has the following general form in a curved spacetime ... [Pg.703]

We have seen in this section that the factorization of Einstein s symmetric, second-rank tensor field equations (10 relations) to a quaternion form (16 relations) not only yields the gravitational and electromagnetic manifestations of matter in a unified field theory but also reveals a feature of quantum mechanics. In particular, it was found that in the flat-space approximation to the curved-space representation in general relativity, the time component of the electromagnetic four-current density corresponds in a one-to-one way with the probability density of quantum mechanics. Its integration over all of space in this limit is found to be unity. [Pg.704]

Figure 3. Changes in resistance with time for four current densities and a PR waveform. Figure 3. Changes in resistance with time for four current densities and a PR waveform.
Figure 5. Changes in stress with time for four current densities and a PR waveform. C denotes an initially compressive film and T denotes an initially tensile film. Figure 5. Changes in stress with time for four current densities and a PR waveform. C denotes an initially compressive film and T denotes an initially tensile film.
A BRIEF INTRODUCTION TO FOUR-CURRENT DENSITY FUNCTIONAL THEORY... [Pg.726]

In the non-relativistic theory, the kinetic energy is T = -EVf/2 >, and T < -t-oo implies n E L T ) for the density n via Sobolev s inequality [3]. The relativistic kinetic energy is (in the Schrodinger representation for ) Tr = ( I X) V j I ), and one is tempted to suppose G (T ). If for instance a bispinor orbital behaves like (f) r , then G implies s < 1 for which indeed Tr < +00. In the above exploited duality theory of Legendre transforms the variational space of admitted potentials is the dual of the variational space of admitted four-current densities, hence A G L T ) must be demanded. For a potential A this implies again s < 1 and hence excludes Coulomb potentials although it permits to treat them as a limiting case. [Pg.729]

The four-current density functional H[J] is split into an orbital variation part K and a density integral L ... [Pg.730]

A semiempirical model that considered only the effect of toluene on kinetics was constructed to describe cell voltage as a fimction of contamination time and current density. The parameters independent of the contamination process, i.e., open circuit voltage (E°), cell resistance (RJ, and Tafel slope (fc), were first estimated based on experimental data in the absence of toluene (giving a baseline). Then these parameters were used to empirically obtain the expressions of two other parameters, and Kcbc/ which accoimted for the effect of toluene contamination on transient and steady-state cell performance, using experimental data at various levels of toluene concentration imder four current densities. The model was validated by comparing the contamination testing results with model-predicted results. Several other definitions were also presented, based on the model, such as the threshold toluene concentration and the degradation rate. [Pg.110]


See other pages where Four-current density is mentioned: [Pg.139]    [Pg.524]    [Pg.725]    [Pg.726]    [Pg.728]    [Pg.730]    [Pg.575]    [Pg.106]    [Pg.164]   
See also in sourсe #XX -- [ Pg.726 , Pg.730 ]




SEARCH



Fermion four-current density

Four-current density functional

Four-current density functional theory

© 2024 chempedia.info