Dirac-K\"ahler approach connected to quantum mechanics in Grassmann space

We compare the way one of us got spinors out of fields, which are a priori antisymmetric tensor fields, to the Dirac-K\"ahler rewriting. Since using our Grassmann formulation is simple it may be useful in describing the Dirac-K\"ahler formulation of spinors and in generalizing it to vector internal degrees of freedom and to charges. The ``cheat'' concerning the Lorentz transformations for spinors is the same in both cases and is put clearly forward in the Grassmann formulation. Also the generalizations are clearly pointed out. The discrete symmetries are discussed, in particular the appearance of two kinds of the time-reversal operators as well as the unavoidability of four families.Comment: 36 page

"An effective two dimensionality" cases bring a new hope to the Kaluza-Klein[like] theories

One step towards realistic Kaluza-Klein[like] theories and a loop hole through the Witten's "no-go theorem" is presented for cases which we call an effective two dimensionality cases: In $d=2$ the equations of motion following from the action with the linear curvature leave spin connections and zweibeins undetermined. We present the case of a spinor in $d=(1+5)$ compactified on a formally infinite disc with the zweibein which makes a disc curved on an almost $S^2$ and with the spin connection field which allows on such a sphere only one massless normalizable spinor state of a particular charge, which couples the spinor chirally to the corresponding Kaluza-Klein gauge field. We assume no external gauge fields. The masslessness of a spinor is achieved by the choice of a spin connection field (which breaks parity), the zweibein and the normalizability condition for spinor states, which guarantee a discrete spectrum forming the complete basis. We discuss the meaning of the hole, which manifests the noncompactness of the space.Comment: 26 pages, 1 figure, an addition which helps to clarify the assumptions and their consequences (the discreteness of spectrum, the massless solution of one handedness,..

A New Form of the Two-Center Integral and its Application in the Semiempirical LCAO MO Method

This reduction was interpreted as a readjustment of cr electrons which then »screen« the Coulomb interaction. A similar correction has been applied to the two-,center integral by Pariser and Parr~ with the polynomial interpolation formula or with-. a form suggested by Nishimoto and Matag

One Particle and Two Particle Distributions in the Liquid-Vapour Interface

Liquid-vapour interface for a simple fluid modelled by the Lennard-Jones potential was treated by the first two mernbers of the Born-Green-Yvon-Bogolyubov hierarchy. The pair of coupled integral equations was solved numerically to get the density profile and the pair correlation function in the inhomogeneous region. It was found that one can get a significant result for the pair correlation function if the monotonous density profile is inserted in the equation determining the pair correlation function. On the other hand, we did not succeed in getting a convergentsolution for the density profile. This means that some further efforts will be necessary to overcome the difficulties connected with the unstable numerical procedures

Molecular Orbital Treatment of HF and HF2 by CND0/2 and INDO

By the development of all electrons semiempirical SCF method it became possible to study in a unique way the changes in electron configuration with the formation of the hydrogen bond. We believe that it is worth making detail calculation using very advanced semiempirical method1 on molecules where the comparison can be made with ab-initio calculation. We made such a calculation on HF and HF2 ion

Fourth virial coefficients of asymmetric nonadditive hard-disc mixtures

The fourth virial coefficient of asymmetric nonadditive binary mixtures of hard disks is computed with a standard Monte Carlo method. Wide ranges of size ratio ($0.05\leq q\leq 0.95$) and nonadditivity ($-0.5\leq \Delta\leq 0.5$) are covered. A comparison is made between the numerical results and those that follow from some theoretical developments. The possible use of these data in the derivation of new equations of state for these mixtures is illustrated by considering a rescaled virial expansion truncated to fourth order. The numerical results obtained using this equation of state are compared with Monte Carlo simulation data in the case of a size ratio $q=0.7$ and two nonadditivities $\Delta=\pm 0.2$.Comment: 9 pages, 7 figures; v2: section on equation of state added; tables moved to supplementary material (http://jcp.aip.org/resource/1/jcpsa6/v136/i18/p184505_s1#artObjSF

Half-widths of the Infrared Bands in Polyethylene

There are a few papers1 treating the temperature dependence of the half- width of IR bands of polymers. The importance of such an experimental work lies in the fact that it is possible to infer from it the mechanism that causes the broadening of the IR bands. The aim of this work is, to report the temperature dependence study of the half-widths of IR bands of polyethylene. The following bands were studied: at 2016 cm-1 (combination band2), at 1080 cm-1 (vibration due to the amorphous polyethylene3) and at 908 cm-1 (vibration of the vinyl end-group3)

Molecular Orbital Treatment of HF and HF2 by CND0/2 and INDO

By the development of all electrons semiempirical SCF method it became possible to study in a unique way the changes in electron configuration with the formation of the hydrogen bond. We believe that it is worth making detail calculation using very advanced semiempirical method1 on molecules where the comparison can be made with ab-initio calculation. We made such a calculation on HF and HF2 ion

Interaction and flocculation of spherical colloids wetted by a surface-induced corona of paranematic order

Particles dispersed in a liquid crystal above the nematic-isotropic phase transition are wetted by a surface-induced corona of paranematic order. Such coronas give rise to pronounced two-particle interactions. In this article, we report details on the analytical and numerical study of these interactions published recently [Phys. Rev. Lett. 86, 3915 (2001)]. We especially demonstrate how for large particle separations the asymptotic form of a Yukawa potential arises. We show that the Yukawa potential is a surprisingly good description for the two-particle interactions down to distances of the order of the nematic coherence length. Based on this fact, we extend earlier studies on a temperature induced flocculation transition in electrostatically stabilized colloidal dispersions [Phys. Rev. E 61, 2831 (2000)]. We employ the Yukawa potential to establish a flocculation diagram for a much larger range of the electrostatic parameters, namely the surface charge density and the Debye screening length. As a new feature, a kinetically stabilized dispersion close to the nematic-isotropic phase transition is found.Comment: Revtex v4.0, 16 pages, 12 Postscript figures. Accepted for publication in Phys. Rev.

Half-widths of the Infrared Bands in Polyethylene

There are a few papers1 treating the temperature dependence of the half- width of IR bands of polymers. The importance of such an experimental work lies in the fact that it is possible to infer from it the mechanism that causes the broadening of the IR bands. The aim of this work is, to report the temperature dependence study of the half-widths of IR bands of polyethylene. The following bands were studied: at 2016 cm-1 (combination band2), at 1080 cm-1 (vibration due to the amorphous polyethylene3) and at 908 cm-1 (vibration of the vinyl end-group3)