Quasimomentum distribution and expansion of an anyonic gas

We point out that the momentum distribution is not a proper observable for a system of anyons in two-dimensions. In view of anyons as Wilczek's composite charged flux-tubes, this is a consequence of the fact that the orthogonal components of the kinetic momentum operator do not commute at the position of a flux tube, and thus cannot be diagonalized in the same basis. As a substitute for the momentum distribution of an anyonic (spatially localized) state, we propose to use the asymptotic single-particle density after expansion of anyons in free space from the state. This definition is identical with the standard one when the statistical parameter approaches that for bosons or fermions. Exact examples of expansion dynamics, which underpin our proposal, and observables that can be used to measure anyonic statistics, are shown.Comment: are welcom

Ispitivanje preciznosti GNSS uređaja Topcon Hiper SR prema normi ISO 17123-8

Konstantan napredak tehnologije donio je velike promjene u geodetsku struku. Jedna od tih promjena je korištenje GNSS mjernih sustava. Danas je moguće ostvariti centimetarsku točnost upravo zahvaljujući neprekidnom razvoju tehnologije kao što je: CROPOS, GPS, GLONASS, uspostava novih satelitskih sustava (Galileo, BeiDou-2) te kvalitetniji i precizniji GNSS prijamnici. Ipak bez obzira na sve navedeno, GNSS prijamnike je, kao i sve ostale instrumente, potrebno ispitati. Svjetska organizacija za normizaciju (ISO) donijela je norme prema kojima se ispituje preciznost GNSS mjernih uređaja te je opisan jedan takav postupak ispitivanja

Theory of classical electrodynamics with topologically quantized singularities as electric charges

We formulate a theory of classical electrodynamics where the only admissible electric charges are topological singularities in the electromagnetic field, and charge quantization is accounted by the Chern theorem, such that Dirac magnetic monopoles are not needed. The theory allows positive and negative charges of equal magnitude, where the sign of the charge corresponds to the chirality of the topological singularity. Given the trajectory ${\bf w}(t)$ of the singularity, one can calculate electric and magnetic fields identical to those produced by Maxwell's equations for a moving point charge, apart from a multiplicative constant factor related to electron charge and vacuum permittivity. The theory is based on the relativistic Weyl equation in frequency-wavevector space, with eigenstates comprising the position, velocity, and acceleration of the singularity, and eigenvalues defining the retarded position of the charge. From the eigenstates we calculate the Berry connection and the Berry curvatures, and identify the curvatures as electric and magnetic fields.Comment: are welcom

work sequence analysis and computer simulations of value flow and workers relocations a case study

Abstract Several solutions have been proposed for the workload balancing in manual assembly lines with workers' task assignment. Facing the case study of a sheet metal assembly line of transport pallets, the paper addresses the problem of the dynamic task assignment. The walking path minimization is considered in the problem, together with task sequence constraints. A real-time simulation allows to test the solution variations before their implementation

ANALYTICAL SOLUTION OF GLOBAL 2D DESCRIPTION OF SHIP GEOMETRY WITH DISCONTINUITIES USING COMPOSITION OF POLYNOMIAL RADIAL BASIS FUNCTIONS

One of the well-known problems in the curves and surfaces reconstruction theory regarding global analytic object description, besides the description of its curvature changes, inflexions and non-bijective parts, is the existence of oscillations near point discontinuities in the middle of the range and at the boundaries of the description. In the ship geometric modelling, ship hull form is usually described globally using parametric methods based on B-spline and NURB-spline, for they have general property of describing discontinuities. Nevertheless, they are not enabling direct, exact calculation of ship\u27s geometric properties, i.e. the calculation of the integrals for determining geometric and other geometry properties or the intersection with water surface. Because of above mentioned, the predominant way of computing geometric properties of the ships is still numerical computation using Simpson integration methods, which also dictates mesh based description of an observed geometry. Analytical solution of global 2D description for ship geometry with discontinuities will be shown in this paper, using the composition of polynomial RBFs, thus solving computational geometry problems, too

Berry phase for a Bose gas on a one-dimensional ring

We study a system of strongly interacting one-dimensional (1D) bosons on a ring pierced by a synthetic magnetic flux tube. By the Fermi-Bose mapping, this system is related to the system of spin-polarized non-interacting electrons confined on a ring and pierced by a solenoid (magnetic flux tube). On the ring there is an external localized delta-function potential barrier $V(\phi)=g \delta(\phi-\phi_0)$. We study the Berry phase associated to the adiabatic motion of delta-function barrier around the ring as a function of the strength of the potential $g$ and the number of particles $N$. The behavior of the Berry phase can be explained via quantum mechanical reflection and tunneling through the moving barrier which pushes the particles around the ring. The barrier produces a cusp in the density to which one can associate a missing charge $\Delta q$ (missing density) for the case of electrons (bosons, respectively). We show that the Berry phase (i.e., the Aharonov-Bohm phase) cannot be identified with the quantity $\Delta q/\hbar \oint \mathbf{A}\cdot d\mathbf{l}$. This means that the missing charge cannot be identified as a (quasi)hole. We point out to the connection of this result and recent studies of synthetic anyons in noninteracting systems. In addition, for bosons we study the weakly-interacting regime, which is related to the strongly interacting electrons via Fermi-Bose duality in 1D systems

Chlorido(η 4-cyclo­octa-1,5-diene)(N,N′-diethyl­thio­urea-κS)rhodium(I)

In the title rhodium(I) complex, [RhCl(C8H12)(C5H12N2S)], N,N′-diethyl­thio­urea acts as a monodenate S-donor ligand. The rhodium(I) coordination sphere is completed by the Cl atom and the COD [= 1,5-cyclo­octa­diene] ligand inter­acting through the π-electrons of the double bonds. If the midpoints of these two bonds are taken into account, the Rh atom exhibits a distorted square-planar coordination. The syn conformation of the N,N′-diethyl­thio­urea ligand with respect to the Cl atom is stabilized by an intra­molecular N—H⋯Cl hydrogen bond. A weak inter­molecular N—H⋯Cl inter­action links mol­ecules along the a axis

Nonsymmetric algebraic Riccati equations associated with an M-matrix: recent advances and algorithms

We survey on theoretical properties and algorithms concerning the problem of solving a nonsymmetric algebraic Riccati equation, and we report on some known methods and new algorithmic advances. In particular, some results on the number of positive solutions are proved and a careful convergence analysis of Newton\u27s iteration is carried out in the cases of interest where some singularity conditions are encountered. From this analysis we determine initial approximations which still guarantee the quadratic convergence