Noncommutativity and theta-locality

In this paper, we introduce the condition of theta-locality which can be used as a substitute for microcausality in quantum field theory on noncommutative spacetime. This condition is closely related to the asymptotic commutativity which was previously used in nonlocal QFT. Heuristically, it means that the commutator of observables behaves at large spacelike separation like $\exp(-|x-y|^2/\theta)$, where $\theta$ is the noncommutativity parameter. The rigorous formulation given in the paper implies averaging fields with suitable test functions. We define a test function space which most closely corresponds to the Moyal star product and prove that this space is a topological algebra under the star product. As an example, we consider the simplest normal ordered monomial $:\phi\star\phi:$ and show that it obeys the theta-locality condition.Comment: LaTeX, 17 pages, no figures; minor changes to agree with published versio

SUPERCOMPUTER SIMULATION OF CRITICAL PHENOMENA IN COMPLEX SOCIAL SYSTEMS

The paper describes a problem of computer simulation of critical phenomena in complex social systems on a petascale computing systems in frames of complex networks approach. The three-layer system of nested models of complex networks is proposed including aggregated analytical model to identify critical phenomena, detailed model of individualized network dynamics and model to adjust a topological structure of a complex network. The scalable parallel algorithm covering all layers of complex networks simulation is proposed. Performance of the algorithm is studied on different supercomputing systems. The issues of software and information infrastructure of complex networks simulation are discussed including organization of distributed calculations, crawling the data in social networks and results visualization. The applications of developed methods and technologies are considered including simulation of criminal networks disruption, fast rumors spreading in social networks, evolution of financial networks and epidemics spreading

Technology and equipment for processing diamond materials of modern electronics

The methods of selection and sorting of diamonds according to their physical properties by modern physical methods of the analysis are developed, as well as the technologies of precision laser cutting of diamonds, their processing on a basis of thermochemical reactions in gas environment. The experimental installation for polishing and grinding of diamond plates, installation for slicing, installation for plasma-chemical processing are created. The techniques of surface roughness measurement of the processed plates and control of roughness parameters are developed. Some experimental results are given

Primary converters microsensor speedups and pressures on diamond materials

The article presents the design, manufacturing techniques and the scheme of parameter measuring of primary transducers for acceleration and pressure microsensors based on diamond materials. There have been described the designing procedure and an experimental way of definition of microsensors' key parameters. The calculated value of capacity 11 пF for primary transducers of the gauge of acceleration, well coincides with experimental values. The working range of accelerations from 100 to 1800 m/s2, thus capacity almost linearly varies in a range 11—20,5 пF. For primary transducers of the pressure sensor the calculated value of capacity 7 пF, also well coincides with experimental values. The working range of pressure measurements from 1 to 19,5 kPa, thus capacity almost linearly varies in a range 6,4—11,7 пF

The retunable SHF-range signal delay line based on ferroelectrics and diamond films

The article describes the principles of creation of a broadband miniature SHF-range signal delay line based on ferroelectrics and diamond films. The parameters of obtained ferroelectrics and diamond films have been given. The possible design of the delay line, executed as a micro strip transfer line of SHF-range signal with the concentrated planar variable capacity condensers is shown

Diamond-made matrix photosensitive elements of ultra-violet range

Principles of construction and technology of creation of matrix photodetecting devices of ultra-violet radiation on the basis of natural diamond are considered. Measurements of spectral, volt-ampere characteristics, of dark current and leakage currents were carried out at various voltages for linear (2×64) and matrix (64×64) photodetecting devices. The basic opportunity of creation of such multielement structures possessing high sensitivity is shown for the first time. It is shown, that surface leakage currents play the dominating role in restriction of photosensivity of the given structures. It is found the significant dispersion of dark current and a photocurrent of matrix photodetectors on the basis of the natural diamond, concerned with heterogeneity of defective structure

Kinetics of intrasubband electron energy relaxation in quantum wells in a quantizing magnetic field

Herein we report the intrasubband relaxation of electron energy in the Landau level system of quantum well as a function of magnetic field strength. The relative role of scattering processes contributing to relaxation kinetics, the electron-electron scattering which redistributes the electrons between Landau levels and the optical phonon emission by the electrons reaching the Landau levels lying near and above the optical phonon energy is revealed. It was shown the most important factor determining the kinetics of energy relaxation is the electron-electron scattering processes, delivering electrons to Landau levels close to optical phonon energy. The flux of these electrons depends on the number of the Landau levels lying below the energy of the optical phonon and increases substantially with a decrease in this number. On the contrary, the electron-phonon scattering rate dependence of the energy relaxation time was found to be much weaker

Features of information erasing from multidisc HDDs by pulse magnetic field

This work presents the research results of information erasing from modern multidisc HDDs by pulse magnetic fields. The quality of information erasing was assessed by methods of atomic force microscopy. The island character of information erasing is explained by shielding of magnetic impulse by metal elements of HDD design. Amplitude and time characteristics of magnetic pulses needed for reliable information erasing from modern multidisc HDDs are defined