摘要:

AbstractLORENTZ‐covariant theories of gravitation which fulfil EINSTEIN's weak principle of equivalence and which contain a pure Newtonian theory as an approximation are tensortheories with the linear approximative form\documentclass{article}\pagestyle{empty}\begin{document}$$ g\mu = - x(\alpha T\mu + [1 - \alpha]\eta \mu vT) $$\end{document}for the field equations. In the case of EINSTEIN's strong principle of equivalence the exact field equations must be the general relativistic EINSTEIN‐equations (or the bimetrical EINSTEIN‐ROSEN‐equations). This follows from the dynamical equations and the BIANCHIidentity according to JÁNOSSYand TREDER.However, from NEWTON's axiom of reaction together with the weak principle of equivalence results that the strong principle of equivalence must be valid for the linear approximation of the field equations with sources. Therefore, the linear approximation of all physically meaningful Lorentz‐covariant theories of gravitation is given by the linearized EINSTEIN‐equations (with HILBERT‐conditions):\documentclass{article}\pagestyle{empty}\begin{document}$$ g\mu = - 2x(T\mu v - \frac{1}{2}\eta \mu T) $$\end{document}, that is by the ansatz α = 2.The main point of our arguments is LAUE's postulate of the self‐consistency of perfect static systems of isolated gravitational masses. In the lowest order of approximation this self‐consistency is only possible if the gravitational matter‐tensor is identical with the special‐relativistic energy‐momentum‐tensorTμv. LAUE's postulate is fulfilled exactly for the general relativistic field equations according to the theorems of BIRKHOFF,

ISSN:0003-3804    

DOI:10.1002/andp.19744860102

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractThe genuine variational principle of macroscopic dissipative continua is generalized to complex scalar fields in the universal form of GAUSSian type. The generalization makes it possible to extend the validity of the principle to the PS field of the non‐relativistic SCHRÖDINGERequation, and to certain types of non‐linear problems. Following MORSE's and FESHBACH's sequence of thoughtful ideas in reverse direction the fundamentals of an “abstract” transport theory, isomorphic with one‐particle quantum theory, are developed and the possibility of interpreting the quantum theory by classical models is discussed. On the basis of new arguments, the impossibility of interpreting quantum mechanics in terms of classical transport theories (hydrodynamical model, diffusional and stochastic models) is e

ISSN:0003-3804    

DOI:10.1002/andp.19744860103

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractA crystal is described by a probability density which is not symmetric regarding the interchange of phase‐space coordinates between two molecules. The set of approximate equations for one‐particle distribution functions with many‐body forces is derived from the LIOUVILLEequation. The expression for the HELMHOLTZfree energy and the equation of state are obtained. The developed method is applied to the determination of the thermodynamic properties of crystalline argon, krypton, and xenon. The nearest‐neighbor distances, internal energies, isothermal and adiabatic compressibilities, linear thermal expansion coefficients, specific heatsCvandCpare calculated using the pair potentials of BARKER‐POMPE, of BARKER‐BOBETIC, and of LENNARD‐JONES, together with the AXILROD‐TELLERthree‐body potential. The obtained results are compared with the experimental d

ISSN:0003-3804    

DOI:10.1002/andp.19744860104

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractAfter a brief description of GYARMATI's Governing Principle of Dissipative Processes, general approximation methods are developed for heat conduction phenomena on two scales. On the first scale the temperature and heat current density fields are approximated by two different sets of functions in such a way that the internal energy balance and the imposed boundary conditions be satisfied. On the second scale we introduce a new temperature field related to the heat current density through the constitutive equation. Since the dissipation potentials in GYARMATI's principle are connected with each other by LEGENDREdual transformations we call “dual field methods” the approximation procedure based on the two temperature fields. It is shown that the equations of the GALERKINmethod, the method of orthogonal projections, and the TREFFTZmethod, when applied to the appropriate problems, are included in the approximation schemes. Due to their great importance a special paragraph is devoted to the treatment of eigenvalue problems. Finally, the approximation methods are illustrated by a simple example and the results are compared with the exact solut

ISSN:0003-3804    

DOI:10.1002/andp.19744860105

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractThe differential cross‐section for the elastic scattering of He4particles on Be9has been studied in the bombarding energy range 1.4‐2.5 MeV.The excitation functions for the elastically scattered α‐particles from Be9were measured at six angles 90°, 125°, 132°, 140°, 150° and 160° in the centre of mass system.A clear and pronounced resonance is observed in the measured cross‐section at incident α‐particle energy 1.93 MeV. Analysis of the data in terms of the single level approximation theory leads to the assignmentJπ = 5+/2 for the observed resonance. Reduced and partial widths for elastic scatteri

ISSN:0003-3804    

DOI:10.1002/andp.19744860106

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractThe structure of singularities of the Veneziano amplitude in the complex angular momentum plane is studied. The introduction of a nonlinear term in the trajectory essentially changes the properties of the partial amplitude as compared to the case of linear trajectories. In theJ‐plane, besides simple poles lying on the leading and on the conventional daughter trajectories, additional poles lying on mirage trajectories (situated below the leading trajectory) emerge. In the partial amplitude also non‐reggeised poles in thes‐plane emerge whose position is independent of the angular momentum. Such are, for example, the ance

ISSN:0003-3804    

DOI:10.1002/andp.19744860107

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY

ISSN:0003-3804    

DOI:10.1002/andp.19744860101

出版商:WILEY‐VCH Verlag    

年代:1974

数据来源: WILEY