An Index Theorem for Domain Walls in Supersymmetric Gauge Theories

The supersymmetric abelian Higgs model with N scalar fields admits multiple domain wall solutions. We perform a Callias-type index calculation to determine the number of zero modes of this soliton. We confirm that the most general domain wall has 2(N-1) zero modes, which can be interpreted as the positions and phases of (N-1) constituent domain walls. This implies the existence of moduli for a D-string interpolating between N D5-branes in IIB string theory.Comment: 9 pages, REVTeX4; v2: reference adde

D-brane Solitons in Supersymmetric Sigma-Models

Massive D=4 N=2 supersymmetric sigma models typically admit domain wall (Q-kink) solutions and string (Q-lump) solutions, both preserving 1/2 supersymmetry. We exhibit a new static 1/4 supersymmetric `kink-lump' solution in which a string ends on a wall, and show that it has an effective realization as a BIon of the D=4 super DBI-action. It is also shown to have a time-dependent Q-kink-lump generalization which reduces to the Q-lump in a limit corresponding to infinite BI magnetic field. All these 1/4 supersymmetric sigma-model solitons are shown to be realized in M-theory as calibrated, or `Q-calibrated', M5-branes in an M-monopole background.Comment: 16 pages, 3 figures, Late

Monopoles in the Higgs Phase

We describe new solutions of Yang-Mills-Higgs theories consisting of magnetic monopoles in a phase with fully broken gauge symmetry. Rather than spreading out radially, the magnetic field lines form flux tubes. The solution is topologically stable and, when embedded in N=2 SQCD, preserves 1/4 of the supercharges. From the perspective of the flux-tube the monopole appears as a kink. Many monopoles may be threaded onto a single flux tube and placed at arbitrary separation to create a stable, BPS necklace of solitons.Comment: 8 Pages, 1 Figure. v2: Added references and comments on 3He. v3: Another reference and corrected term in Lagrangia

Розробка нейромережевої інтелектуальної системи для прогнозування енергетичних центрів плямових зображень у процесах профілювання лазерного променя

Здійснено розробку нейромережевої інтелектуальної системи для прогнозування енергетичних центрів (ЕЦ) плямових зображень у процесах профілювання лазерного променя (ЛП). Обґрунтовано актуальність задачі прогнозування координат ЕЦ профілю ЛП. Розглянуто методи прогнозування та обґрунтовано доцільність застосування нейромережевої моделі. Здійснено комп’ютерне моделювання системи прогнозування, а також на основі отриманих результатів сформульовано вимоги та здійснено програмну реалізацію інтелектуальної системи.Выполнено разработку нейросетевой интеллектуальной системы для прогнозирования энергетических центров (ЭЦ) пятенных зображений в процесах профилирования лазерного луча (ЛЛ). Обоснована актуальность задачи прогнозирования координат ЭЦ профиля ЛЛ. Рассмотрены методы прогнозирования и обоснована целесообразность применения нейросетевой модели. Выполнено компьютерное моделирование системы прогнозирования, а также на основе полученных результатов сформулированы требования и выполнено программную реализацию интеллектуальной системы.The development of a neural net intellectual system for energy centers (EC) spot images forecasting in the processes of laser beam profiling (LB) is done. Actuality of the problem of coordinates forecasting of EC of laser beam profile is proved. Methods of forecasting are considered and the appropriateness of usage the neural net model is justified. Computer simulation of forecasting system is carried out and also on the basis of the obtained results the requirements are formulated and software implementation of intelligent system is performed

Patterns on liquid surfaces: cnoidal waves, compactons and scaling

Localized patterns and nonlinear oscillation formation on the bounded free surface of an ideal incompressible liquid are analytically investigated . Cnoidal modes, solitons and compactons, as traveling non-axially symmetric shapes are discused. A finite-difference differential generalized Korteweg-de Vries equation is shown to describe the three-dimensional motion of the fluid surface and the limit of long and shallow channels one reobtains the well known KdV equation. A tentative expansion formula for the representation of the general solution of a nonlinear equation, for given initial condition is introduced on a graphical-algebraic basis. The model is useful in multilayer fluid dynamics, cluster formation, and nuclear physics since, up to an overall scale, these systems display liquid free surface behavior.Comment: 14 pages RevTex, 5 figures in p

Flamelet/flow interaction in premixed turbulent flames - Simultaneous measurements of gas velocity and flamelet position

An experimental technique for obtaining simultaneous measurements of fluid velocity and flamelet position in premixed flames is described and applied in a turbulent V-flame. The flamelet position information is used to calculate conditional velocity statistics, conditional on both zone (reactants or products) as well as conditional on distance from the flamelet. The conditional zone statistics demonstrate that increases (or decreases) in turbulence across the flame are dependent on axial position and location within the flame brush. The product- zone conditional covariance, coupled with the measured conditional mean velocity profiles, indicate that turbulence generation by shear may be a significant contribution to product zone turbulence levels. Velocity statistics conditional on distance from the flamelet demonstrate a considerable interaction between the flamelet and velocity field. Man and rms velocities vary significantly with proximity to the flamelet, such that differences in velocities which which occur just across the flamelet surface. The change in rms velocities just across the flamelet is found to be anisotropic, with the largest increase (smallest decrease) occurring in the axial velocity component. Rms velocities conditional on flamelet position further support the hypothesis that increased product gas velocity fluctuations may have a significant component associated with turbulence generation by mean shear

Saturation in heteronuclear photoassociation of 6Li7Li

We report heteronuclear photoassociation spectroscopy in a mixture of magneto-optically trapped 6Li and 7Li. Hyperfine resolved spectra of the vibrational level v=83 of the singlet state have been taken up to intensities of 1000 W/cm^2. Saturation of the photoassociation rate has been observed for two hyperfine transitions, which can be shown to be due to saturation of the rate coefficient near the unitarity limit. Saturation intensities on the order of 40 W/cm^2 can be determined.Comment: 5 pages, 3 figures, to appear in Phys. Rev. A (Rapid Communication

Constraining Sources of Ultra High Energy Cosmic Rays Using High Energy Observations with the Fermi Satellite

We analyze the conditions that enable acceleration of particles to ultra-high energies, ~10^{20} eV (UHECRs). We show that broad band photon data recently provided by WMAP, ISOCAM, Swift and Fermi satellites, yield constraints on the ability of active galactic nuclei (AGN) to produce UHECRs. The high energy (MeV - GeV) photons are produced by Compton scattering of the emitted low energy photons and the cosmic microwave background or extra-galactic background light. The ratio of the luminosities at high and low photon energies can therefore be used as a probe of the physical conditions in the acceleration site. We find that existing data excludes core regions of nearby radio-loud AGN as possible acceleration sites of UHECR protons. However, we show that giant radio lobes are not excluded. We apply our method to Cen A, and show that acceleration of protons to ~10^{20} eV can only occur at distances >~ 100 kpc from the core.Comment: Extended discussion on former results; Accepted for publication in JCA

Domain Wall Junction in N=2 Supersymmetric QED in four dimensions

An exact solution of domain wall junction is obtained in N=2 supersymmetric (SUSY) QED with three massive hypermultiplets. The junction preserves two out of eight SUSY. Both a (magnetic) Fayet-Iliopoulos (FI) term and complex masses for hypermultiplets are needed to obtain the junction solution. There are zero modes corresponding to spontaneously broken translation, SUSY, and U(1). All broken and unbroken SUSY charges are explicitly worked out in the Wess-Zumino gauge in N=1 superfields as well as in components. The relation to models in five dimensions is also clarified.Comment: 27 pages, 6 figures, comments on zero modes added, a few references adde

Simultaneous Magneto-Optical Trapping of Two Lithium Isotopes

We confine 4 10^8 fermionic 6Li atoms simultaneously with 9 10^9 bosonic 7Li atoms in a magneto-optical trap based on an all-semiconductor laser system. We optimize the two-isotope sample for sympathetic evaporative cooling. This is an essential step towards the production of a quantum-degenerate gas of fermionic lithium atoms.Comment: 4 pages, 3 figure