474 research outputs found

    Symplectic areas, quantization, and dynamics in electromagnetic fields

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    A gauge invariant quantization in a closed integral form is developed over a linear phase space endowed with an inhomogeneous Faraday electromagnetic tensor. An analog of the Groenewold product formula (corresponding to Weyl ordering) is obtained via a membrane magnetic area, and extended to the product of N symbols. The problem of ordering in quantization is related to different configurations of membranes: a choice of configuration determines a phase factor that fixes the ordering and controls a symplectic groupoid structure on the secondary phase space. A gauge invariant solution of the quantum evolution problem for a charged particle in an electromagnetic field is represented in an exact continual form and in the semiclassical approximation via the area of dynamical membranes.Comment: 39 pages, 17 figure

    Cotangent bundle quantization: Entangling of metric and magnetic field

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    For manifolds M\cal M of noncompact type endowed with an affine connection (for example, the Levi-Civita connection) and a closed 2-form (magnetic field) we define a Hilbert algebra structure in the space L2(TM)L^2(T^*\cal M) and construct an irreducible representation of this algebra in L2(M)L^2(\cal M). This algebra is automatically extended to polynomial in momenta functions and distributions. Under some natural conditions this algebra is unique. The non-commutative product over TMT^*\cal M is given by an explicit integral formula. This product is exact (not formal) and is expressed in invariant geometrical terms. Our analysis reveals this product has a front, which is described in terms of geodesic triangles in M\cal M. The quantization of δ\delta-functions induces a family of symplectic reflections in TMT^*\cal M and generates a magneto-geodesic connection Γ\Gamma on TMT^*\cal M. This symplectic connection entangles, on the phase space level, the original affine structure on M\cal M and the magnetic field. In the classical approximation, the 2\hbar^2-part of the quantum product contains the Ricci curvature of Γ\Gamma and a magneto-geodesic coupling tensor.Comment: Latex, 38 pages, 5 figures, minor correction

    Graphene as a quantum surface with curvature-strain preserving dynamics

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    We discuss how the curvature and the strain density of the atomic lattice generate the quantization of graphene sheets as well as the dynamics of geometric quasiparticles propagating along the constant curvature/strain levels. The internal kinetic momentum of Riemannian oriented surface (a vector field preserving the Gaussian curvature and the area) is determined.Comment: 13p, minor correction

    Quantum Magnetic Algebra and Magnetic Curvature

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    The symplectic geometry of the phase space associated with a charged particle is determined by the addition of the Faraday 2-form to the standard structure on the Euclidean phase space. In this paper we describe the corresponding algebra of Weyl-symmetrized functions in coordinate and momentum operators satisfying nonlinear commutation relations. The multiplication in this algebra generates an associative product of functions on the phase space. This product is given by an integral kernel whose phase is the symplectic area of a groupoid-consistent membrane. A symplectic phase space connection with non-trivial curvature is extracted from the magnetic reflections associated with the Stratonovich quantizer. Zero and constant curvature cases are considered as examples. The quantization with both static and time dependent electromagnetic fields is obtained. The expansion of the product by the deformation parameter, written in the covariant form, is compared with the known deformation quantization formulas.Comment: 23 page

    Appliacation of the Kalman filter in control systems of power electronics

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    Kalman filter can deal with measurement and modelling inaccuracies and, also, can be used for the join state estimation.Higher accuracy of the parameters estimation of a control object can increase the power efficiency of control systems in inverter-fed drives. This paper introduces the improved extended Kalman Filter (EKF) for the real-time speed estimation of an induction motor (IM) in the sensorless control system of inverter-fed drive.Key words: power electronics, inverter-fed drive, extended Kalman Filter, sensorless vectorcontrol system, microcontroller

    Analogues of the central point theorem for families with dd-intersection property in Rd\mathbb R^d

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    In this paper we consider families of compact convex sets in Rd\mathbb R^d such that any subfamily of size at most dd has a nonempty intersection. We prove some analogues of the central point theorem and Tverberg's theorem for such families
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