On Possible Measurement of Gravitational Interaction Parameters on Board a Satellite

The recently suggested SEE (Satellite Energy Exchange) method of measuring the gravitational constant $G$, possible equivalence principle violation (measured by the E\"{o}tv\"{o}s parameter $\eta$) and the hypothetic 5th force parameters $\alpha$ and $\lambda$ on board a drag-free Earth's satellite is discussed and further developed. Various particle trajectories near a heavy ball are numerically simulated. Some basic sources of error are analysed. The $G$ measurement procedure is modelled by noise insertion to a ``true'' trajectory. It is concluded that the present knowledge of $G, \alpha$ (for $\lambda \geq 1$ m) and $\eta$ can be improved by at least two orders of magnitude.Comment: (only two misprints on title page) 7 page

Constraints from orbital motions around the Earth of the environmental fifth-force hypothesis for the OPERA superluminal neutrino phenomenology

It has been recently suggested by Dvali and Vikman that the superluminal neutrino phenomenology of the OPERA experiment may be due to an environmental feature of the Earth, naturally yielding a long-range fifth force of gravitational origin whose coupling with the neutrino is set by the scale M_*, in units of reduced Planck mass. Its characteristic length lambda should not be smaller than one Earth's radius R_e, while its upper bound is expected to be slightly smaller than the Earth-Moon distance (60 R_e). We analytically work out some orbital effects of a Yukawa-type fifth force for a test particle moving in the modified field of a central body. Our results are quite general since they are not restricted to any particular size of lambda; moreover, they are valid for an arbitrary orbital configuration of the particle, i.e. for any value of its eccentricity $e$. We find that the dimensionless strength coupling parameter alpha is constrained to |alpha| <= 1 10^-10-4 10^-9 for 1 R_e <= lambda <= 10 R_e by the laser data of the Earth's artificial satellite LAGEOS II, corresponding to M_* >= 4 10^9 -1.6 10^10. The Moon perigee allows to obtain |alpha| <= 3 10^-11 for the Earth-Moon pair in the range 15 R_e <= lambda = 3 10^10 - 4.5 10^10. Our results are neither necessarily limited to the superluminal OPERA scenario nor to the Dvali-Vikman model, in which it is M_* = 10^-6 at lambda = 1 R_e, in contrast with our bounds: they generally extend to any theoretical scenario implying a fifth-force of Yukawa-type.Comment: LaTex2e, 18 pages, 4 figures, 1 table, 81 reference

ВЛИЯНИЕ МОРФОЛОГИИ НА ЭЛЕКТРОННЫЕ СВОЙСТВА -ОРИЕНТИРОВАННЫХ GaAs, GaP, GaSb, InAs, InP и InSb НАНОШНУРОВ

The results of calculations by means of the first principles methods of the -oriented GaP, GaAs, GaSb, InP, InAs, and InSb nanowires with zince-blende structure show that the morphology of nanowires affects their electronic properties. It has been established that for nanowires with {011} facets the formation of small-sized {112} edges between adjacent {011} facets results in a stable structure and removes the surface states in the band-gap area without the hydrogen passivation.Приведены результаты расчетов методами из первых принципов -ориентированных GaP, GaAs, GaSb, InP, InAs и InSb наношнуров со структурой цинковой обманки, которые показывают, что морфология таких наношнуров кардинально влияет на их электронные свойства. Установлено, что для наношнуров с {011} гранями на поверхности формирование небольших по размеру {112} кромок между соседними {011} гранями приводит к более стабильной структуре и удаляет поверхностные состояния в районе запрещенной зоны без пассивации водородом

Possible variations of the fine structure constant α\alpha and their metrological significance

We briefly review the recent experimental results on possible variations of the fine structure constant $\alpha$ on the cosmological time scale and its position dependence. We outline the theoretical grounds for the assumption that $\alpha$ might be variable, mention some phenomenological models incorporating a variable $\alpha$ into the context of modern cosmology and discuss the significance of possible $\alpha$ variations for theoretical and practical metrology.Comment: Latex, 17 pages, brief review. References updated, minor errors remove

EFFECT OF MORPHOLOGY ON ELECTRONIC PROPERTIES OF THE <111> -ORIENTED GaAs, GaP, GaSb, InAs, InP AND InSb NANOWIRES

The results of calculations by means of the first principles methods of the -oriented GaP, GaAs, GaSb, InP, InAs, and InSb nanowires with zince-blende structure show that the morphology of nanowires affects their electronic properties. It has been established that for nanowires with {011} facets the formation of small-sized {112} edges between adjacent {011} facets results in a stable structure and removes the surface states in the band-gap area without the hydrogen passivation