Multi electron effects in the spectra of inelastic scattering of fast electrons in metals (I)
Multi electron effects in the spectra of inelastic scattering of fast electrons in metals (I)
F.A. Zhivopistsev and F.E. Komas
Inelastic scattering of electrons in metals (e, e') is studied. It is shown that the dynamic form-factor, taking into account the transition of an electron from an atomic level to the Fermi surface, can be expressed in terms of the twoparticle Green function (in the channel the electron of the conduction band is an inner hole), in which case the expression for the dynamic form-factor holds over the whole frequency range of the spectrum (not only at the absorption edge).
Show AbstractThe one-ion model and the magnetostriction of terbium and its gadolinium alloy
The one-ion model and the magnetostriction of terbium and its gadolinium alloy
S.A. Nikitin, S.M. Nakvi and D. Kim
We measure the temperature dependence of the magnetostriction, the magnetostrictive contribution to the thermal expansion, and that of the magnetization of monocrystalline terbium and the alloy Tb_0,5Gd_0,5. We find that the experimental data agree with the predictions of the one-ion theory as regards the temperature dependence of the magnetostrictive contribution to the thermal expansion. We calculate from experimental data and thermodynamic relations the dependence of the transition temperature and the magnetic-crystalline interaction on the lattice parameters. We demonstrate the agreement of these relationships with estimates made according to the theory of the crystalline field using the one-ion model.
Show AbstractCausality and regularization
Causality and regularization
V.A. Il'in, M.S. Imashev, and D.A. Slavnov
Within the framework of perturbation theory it is shown that the integral condition of causality is satisfied for a regularized scattering matrix.
Show AbstractA multilayer interference absorber with a working layer of arbitrary thickness
A multilayer interference absorber with a working layer of arbitrary thickness
Yu.A. Pirogov and A.V. Tikhonravov
The conditions for maximum energy absorption, and equations for the selectivity of a multilayer interference absorber with a working layer of arbitrary thickness are obtained. It is shown that to synthesize a multilayer interference absorber with a specified selectivity (absorption band) one must choose the multilayer dielectric mirrors which surround the working layer with the required dispersion of the phase of the reflection coefficient, or vary the thickness of the working layer.
Show AbstractNMR spectra in the strong-coupling region
NMR spectra in the strong-coupling region
V.S. Tumanov
A method of calculating high-resolution NMR spectra in the region of strong spin-spin coupling is described. It is shown that in the general case one can determine the number of spectral lines and the Intensities of these lines. The forms of the spectra for which the calculation is carried out in analytical form are indicated. АаВb and ABC spectra are considered as examples.
Show AbstractCorrect use of the palatini principle in gravitational theories
Correct use of the palatini principle in gravitational theories
V.N. Ponomarev and A.A. Tseitlin
It is shown that the correct variational problem in metric theory of gravitations, based on independent variation with respect to the coefficient of affine connectivity, is equivalent to the problem of finding the conditional extremum of the functional of the action S= ∫_Ω√(-g)Rd^4x.
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