Zel'dovich states with very small mass and charge in nonlinear electrodynamics coupled to gravity

It is shown that in non-linear electrodynamics (in particular, Born-Infeld one) in the framework of general relativity there exist "weakly singular" configurations such that (i) the proper mass M is finite in spite of divergences of the energy density, (ii) the electric charge q and Schwarzschild mass m ~ q can be made as small as one likes, (iv) all field and energy distributions are concentrated in the core region. This region has an almost zero surface area but a finite longitudinal size L=2M. Such configurations can be viewed as a new version of a classical analogue of an elementary particle.Comment: 11 pages. 1 reference added. To appear in Grav. Cosm

Bunch-excited wakefield in dielectric waveguide with hollow plasma channel

Wakefield excitation by a single relativistic electron bunch in a plasma-dielectric accelerating structure has been studied both analytically and numerically. The structure represents a dielectric-loaded cylindrical metal waveguide, which has partially plasma-filled channel (the hollow plasma channel) to transport charged particles. Assuming the linear regime of excitation, analytical expressions have been derived for the longitudinal and radial wakefields generated by a finite-size electron bunch. Axial profiles of wakefield component amplitudes have been studied, and their mode and spectrum analyses have been performed. Furthermore, the electron bunch-driven wakefield excitation has been PIC-simulated numerically for the quasi-linear regime. The comparative analysis of the data resulting from analytical studies and the ones obtained by numerical simulation has demonstrated qualitative agreement between the results

Reversible Logic Circuit Synthesis

Reversible or information-lossless circuits have applications in digital signal processing, communication, computer graphics and cryptography. They are also a fundamental requirement in the emerging field of quantum computation. We investigate the synthesis of reversible circuits that employ a minimum number of gates and contain no redundant input-output line-pairs (temporary storage channels). We prove constructively that every even permutation can be implemented without temporary storage using NOT, CNOT and TOFFOLI gates. We describe an algorithm for the synthesis of optimal circuits and study the reversible functions on three wires, reporting distributions of circuit sizes. We study circuit decompositions of reversible circuits where gates of the same type are next to each other. Finally, in an application important to quantum computing, we synthesize oracle circuits for Grover's search algorithm, and show a significant improvement over a previously proposed synthesis algorithm.Comment: 30 pages, 14 figs+tables. To appear in IEEE Transactions on Computer-Aided Design of Electronic Circuits. Contains results presented at the Intl. Conf. on Computer-Aided Design, 2002 and new material on decompositions of reversible circuits where gates of the same type are next to each othe

Hadron and Quark Form Factors in the Relativistic Harmonic Oscillator Model

Nucleon, pion and quark form factors are studied within the relativistic harmonic oscillator model including the quark spin. It is shown that the nucleon charge, magnetic and axial form factors and the pion charge form factor can be explained with one oscillator parameter if one accounts for the scaling rule and the size of the constituent quarks.Comment: 9 pages, Latex, 3 postscript figures, DFTT 8/9

The Boltzmann equation for colourless plasmons in hot QCD plasma. Semiclassical approximation

Within the framework of the semiclassical approximation, we derive the Boltzmann equation describing the dynamics of colorless plasmons in a hot QCD plasma. The probability of the plasmon-plasmon scattering at the leading order in the coupling constant is obtained. This probability is gauge-independent at least in the class of the covariant and temporal gauges. It is noted that the structure of the scattering kernel possesses important qualitative difference from the corresponding one in the Abelian plasma, in spite of the fact that we focused our study on the colorless soft excitations. It is shown that four-plasmon decay is suppressed by the power of $g$ relative to the process of nonlinear scattering of plasmons by thermal particles at the soft momentum scale. It is stated that the former process becomes important in going to the ultrasoft region of the momentum scale.Comment: 41, LaTeX, minor changes, identical to published versio

Optical extinction, refractive index, and multiple scattering for suspensions of interacting colloidal particles

We provide a general microscopic theory of the scattering cross-section and of the refractive index for a system of interacting colloidal particles, exact at second order in the molecular polarizabilities. In particular: a) we show that the structural features of the suspension are encoded into the forward scattered field by multiple scattering effects, whose contribution is essential for the so-called "optical theorem" to hold in the presence of interactions; b) we investigate the role of radiation reaction on light extinction; c) we discuss our results in the framework of effective medium theories, presenting a general result for the effective refractive index valid, whatever the structural properties of the suspension, in the limit of particles much larger than the wavelength; d) by discussing strongly-interacting suspensions, we unravel subtle anomalous dispersion effects for the suspension refractive index.Comment: Submitted to Journal of Chemical Physics 37 pages, 4 figure

Взаємодія 4,5-диформіл-2,3,6,7,8,10-гексагідроакридин-8а(1Н)-карбонітрилу з N-нуклеофілами

Schiff bases are of practical interest as initial materials both for the combinatorial synthesis for libraries of compounds, and for preparation of complexes with metals; thus, currently the intensity of research in this direction is increasing. The possibilities of practical use of complex compounds with organic ligands are quite broad varying from effective catalysts of various chemical processes to molecular sensors. While studying formylation of 5,6,7,8-tetrahydro-1H-spiro[cyclohexane-1,2-quinazolin]-4’(3’H)-one a new domino reaction, which makes it possible to obtain tricyclic acridine systems, has been carried out. In spite of the reduced electrophilicity of the aldehyde groups in 4,5-diformyl-2,3,6,7,8,10-hexahydroacridine-8а(1H)-carbonitrile the latter is shown to react with various amines in benzene with azeotropic removal of water using p-TsOH as a catalyst, and with hydroxylamine hydrochloride in i-PrOH. New Schiff bases and oxime obtained are of potential interest as ligands for formation of chelate complexes. The reaction of dialdehyde with N2H4×H2O instead of the expected hydrazone resulted in obtaining a macrocyclic compound – a derivative of hexaazacyclooctadecine. The structure of the compounds obtained corresponds to the data of 1H NMR-spectroscopy, mass spectrometry and elemental analysis. The preliminary studies have shown that azomethines – 4,5-phenyl(cyclohexcyl)iminomethyl-2,3,6,7,8,10-hexahydroacridine8а(1H)-carbonitrile create complexes with copper and nickel ions.Основания Шиффа представляют практический интерес в качестве исходных как для комбинаторного синтеза библиотек веществ, так и для создания комплексов с металлами, и в последнее время интенсивность исследований в данном направлении только увеличивается. Возможности практического использования комплексных соединений с органическими лигандами весьма широки: от эффективных катализаторов различных химических процессов до молекулярных сенсоров. В ходе изучения формилирования 5’,6’,7’,8’-тетрагидро-1’Н-спиро[циклогексан-1,2’-хиназолин]-4’(3’Н)-она нами была найдена новая домино-реакция, которая позволяет выйти на трициклические гидрированные акридиновые системы. Показано, что несмотря на сниженную электрофильность альдегидных групп в 4,5-диформил2,3,6,7,8,10-гексагидроакридин-8а(1Н)-карбонитриле, он реагирует с различными аминами в бензоле с азеотропной отгонкой воды с применением в качестве катализатора p-TsOH, а также с солянокислым гидроксиламином в i-PrOH. Полученные основания Шиффа и оксим представляют потенциальный интерес в качестве лигандов для образования хелатных комплексов. В результате реакции диальдегида с N2H4×H2O вместо ожидаемого гидразона получено макроциклическое соединение – производное гексаазациклооктадецина. Строение всех полученных соединений согласуется с данными ЯМР 1Н-спектроскопии, масс-спектрометрии и элементного анализа. Предварительные исследования показали, что азометины − 4,5-фенил(циклогексил)иминометил-2,3,6,7,8,10-гексагидроакридин-8а(1Н)карбонитрила образуют комплексные соединения с ионами никеля и меди. Основи Шиффа становлять практичний інтерес в якості вихідних як для комбінаторного синтезу бібліотек речовин, так і для створення комплексів з металами, і останнім часом інтенсивність досліджень у даному напрямку тільки збільшується. Можливості практичного використання комплексів з органічними лігандами досить широкі: від ефективних каталізаторів хімічних процесів до молекулярних сенсорів. У ході вивчення формілювання 5’,6’,7’,8’-тетрагідро-1’Н-спіро[циклогексан-1,2’-хіназолін]-4’(3’Н)-ону нами була відкрита нова доміно-реакція, яка дозволяє вийти на трициклічні гідровані акридинові системи. Показано, що незважаючи на знижену електрофільність альдегідних груп у 4,5-диформіл-2,3,6,7,8,10-гексагідроакридину-8а(1Н)-карбонітрилі, він реагує з різними амінами у бензолі з азеотропною відгонкою води з використанням в якості каталізатора p-TsOH, а також з солянокислим гідроксиламіном у i-PrOH. Отримані основи Шиффа та оксим становлять потенційний інтерес у якості лігандів для утворення хелатних комплексів. У результаті реакції діальдегіду з N2H4×H2O замість очікуваного гідразону отримано макроциклічну сполуку – похідну гексаазациклооктадецину. Будова всіх отриманих сполук підтверджена даними ЯМР 1Н-спектроскопії, мас-спектрометрії і елементного аналізу. Попередні дослідження продемонстрували, що азометини – 4,5-феніл(циклогексил)імінометил-2, 3,6,7,8,10-гексагідроакридин-8а(1Н)-карбонітрилу утворюють комплексні сполуки з іонами нікелю та міді

Singularity-free model of electric charge in physical vacuum: Non-zero spatial extent and mass generation

We propose a model of a spinless electrical charge as a self-consistent field configuration of the electromagnetic (EM) field interacting with a physical vacuum effectively described by the logarithmic quantum Bose liquid. We show that, in contrast to the EM field propagating in a trivial vacuum, a regular solution does exist, and both its mass and spatial extent emerge naturally from dynamics. It is demonstrated that the charge and energy density distribution acquire Gaussian-like form. The solution in the logarithmic model is stable and energetically favourable, unlike that obtained in a model with a quartic (Higgs-like) potential.Comment: 10 pages, 9 figures, final/published versio