The relativistic semi-group,Lorentz group,and tachyons. I

It is claimed that the current interest of tachyons and some of their unusual properties may be the result of an insufficient mathematical formalism based on Lorentz groups. The introduction of tachyons requires not only a generalization of the principle of causality, but also an extension of the principle of relativistic invariance. A method is proposed to remove a number of problematic cases in the treatment of tachyons.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 85–88, May, 1976.The author wishes to express his appreciation to D. D. Ivanenko for consideration and constructive criticism.     

Point defect generation,nano-void formation and growth. I. Validation

The volume fraction of point defects generated as a function of plastic shear strain squared, γ², was derived from crystal plasticity concepts. The evolution was determined from the stress–strain values using a new constitutive relation which replicates the measured behavior with at least two fitted loci. Assuming that nano-voids form by clustering of vacancies, the nano-void diameter was found to be proportional to their spacing and shear strain with the constant being characteristic of point defect production during deformation. The predicted amount of point defect generated was validated using the previously determined resistivity of [100] copper single crystals deformed at 4.2?K and annealed at 296?K. Similar analysis of super-pure polycrystalline copper data affirmed that the dynamic annihilation parameter extrinsically incorporated in the new derivation is larger due to formation of slip clusters. Moreover, the temperature dependence of the mean slip-distance to inter-forest spacing ratio at Stage II to III transition indicates that the thermally activated drag of vacancy-creating jogs occurs above 150?K. For polycrystalline aluminum deformed at 296?K, it was concluded that the nuclei of the nano-voids were not part of the evolving dislocation array but were embedded in the grown-in microstructure. This hypothesis is pursued in the accompanying paper, Part II, and its prediction results in a criterion for ductile failure.     

Cosmological origin of irreversibility,time, and time anisotropies. I

Causal links among the thermodynamic, electrodynamic, and cosmological arrows of time are explained within the framework of a new theory derived from Newtonian gravitation or general relativistic theory. The master asymmetry so derived is employed to deduce the second postulate of thermodynamics in terms of dissipation function or entropic growth. Discussing Olbers' paradox and employing a laboratory-universe principle of equivalence, the theory demonstrates how the expansion of our isotropic universe affects all irreversible processes on earth. Gravitation and the observed expanding space become the indirect causes of thermal gradients and irreversible processes channeling energy from planetary and galactic cores, through colder regions, all the way into the unsaturable sink of expanding intergalactic space. The new formulations replace the axiomatic formalisms of classical and continuum thermodynamics. The fundamental role played by the expansion (bulk) viscosity is stressed. Other possible interactions among cosmology, thermodynamics, and electrodynamics are reviewed and analyzed from a new viewpoint.     

Complex geometry,unification, and quantum gravity. I. The geometry of elementary particles

The Poincaré group is replaced byU(3, 2), the pseudounitary extension of the de Sitter groupSO(3, 2), as internal and space-time symmetries are combined in a geometric setting which invalidates the no-go theorems. A new model of elementary particles as vertical vectors on the principal fiber bundleU(3, 2) U(3, 2)/U(3, 1)×U(1) is introduced and their interactions via Lie bracket analyzed. The model accounts for the four known superselection rules: spin, electric charge, baryon number, and lepton number.     

Intersubjectivity,relativistic covariance,and conditionals: response to C. I. J. M. Stuart

A misunderstanding persists between Stuart and me, which I do my best to clarify. Bayesian inverse subjectivities versus relativistic covariance and physical intersubjectivity are discussed. A joint number of chances formalism taking care of the propagation of the probability of causes is proposed.     

High-pressure gas lasers on Ar I,Xe I,and Kr I transitions

Lasing has been obtained in a high pressure (up to 17 atm) gas on Ar I, Xe I, and Kr I transitions. The gas was excited by a transverse discharge with volume preionization by a discharge through a dielectric. New laser lines belonging to Ar I (9123, 9658, 10470, and 11488 Å), Xe I (8232 Å), and Kr I (8929 Å) have been found. The dependences of the spectral and energetic characteristics of the He-Ar laser on the conditions of gas pressure and discharge have been investigated in detail. At high pressures, wide (about 50 HGz) laser lines have been found as well as high power (>10⁵ W) laser lines. Time characteristics of the radiation have been investigated and optimal conditions for the generation power have been defined.     

Single crystal nickel ferrite films. I. Film preparation,structure and composition

Single crystal Ni ferrite films were prepared by a chemical transport reaction in sandwich arrangement. The technological conditions, the problems of their chemical composition, the structure and the quality of their surface were studied with respect to a further investigation of the magnetic properties of these ferrite films.I would like to thank to Dr. L. ervinka and to M. Janatka for carrying out the X-ray and electron diffraction. My thanks belong also to A. Novák for performing the chemical analysis of the initial nickel ferrite and to the workers in the VUST Laboratory who made some partial measurements.     

Geometry and analysis on isospectral sets. I. Riemannian geometry,asymptotic case

A short introduction to the analytical and algebraic aspects of integrable systems is given. We consider the Riemannian geometry of the isospectral set belonging to the Dirichlet problem −y′' + q(x)y = λy, y(0) = y(1) = 0, where q is a square integrable function of the real Hilbert space L²_ℝ([0,1]). We derive the metric and the connection for the isospectral set, which is an infinite dimensional real analytic submanifold of LL²_ℝ([0,1 ]), in the case of large eigenvalues. The curvature in the asymptotic case is then derived and it is proved that the connection and the curvature are well defined if we take their coefficients in the discrete Sobolev spaces. We further give the explicit formulae for the parallel transport and a sufficiency condition is derived such that a curve on the isospectral set is a geodesic.