2,379 research outputs found

    Dynamic speckle - Interferometry of micro-displacements

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    The problem of the dynamics of speckles in the image plane of the object, caused by random movements of scattering centers is solved. We consider three cases: 1) during the observation the points move at random, but constant speeds, and 2) the relative displacement of any pair of points is a continuous random process, and 3) the motion of the centers is the sum of a deterministic movement and random displacement. For the cases 1) and 2) the characteristics of temporal and spectral autocorrelation function of the radiation intensity can be used for determining of individually and the average relative displacement of the centers, their dispersion and the relaxation time. For the case 3) is showed that under certain conditions, the optical signal contains a periodic component, the number of periods is proportional to the derivations of the deterministic displacements. The results of experiments conducted to test and application of theory are given. © 2012 American Institute of Physics

    GL_q(N)-covariant braided differential bialgebras

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    We study a possibility to define the (braided) comultiplication for the GLq(N)-covariant differential complexes on some quantum spaces. We discover such `differential bialgebras' (and Hopf algebras) on the bosonic and fermionic quantum hyperplanes (with additive coproduct) and on the braided matrix algebra BMq(N) with both multiplicative and additive coproducts. The latter case is related (for N=2) to the q-Minkowski space and q-Poincare algebra.Comment: 7 page

    Some Remarks on Producing Hopf Algebras

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    We report some observations concerning two well-known approaches to construction of quantum groups. Thus, starting from a bialgebra of inhomogeneous type and imposing quadratic, cubic or quartic commutation relations on a subset of its generators we come, in each case, to a q-deformed universal enveloping algebra of a certain simple Lie algebra. An interesting correlation between the order of initial commutation relations and the Cartan matrix of the resulting algebra is observed. Another example demonstrates that the bialgebra structure of sl_q(2) can be completely determined by requiring the q-oscillator algebra to be its covariant comodule, in analogy with Manin's approach to define SL_q(2) as a symmetry algebra of the bosonic and fermionic quantum planes.Comment: 6 pages, LATEX, no figures, Contribution to the Proceedings of the 4th Colloquium "Quantum Groups and Integrable Systems" (Prague, June 1995

    First Evaluation of the CPU, GPGPU and MIC Architectures for Real Time Particle Tracking based on Hough Transform at the LHC

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    Recent innovations focused around {\em parallel} processing, either through systems containing multiple processors or processors containing multiple cores, hold great promise for enhancing the performance of the trigger at the LHC and extending its physics program. The flexibility of the CMS/ATLAS trigger system allows for easy integration of computational accelerators, such as NVIDIA's Tesla Graphics Processing Unit (GPU) or Intel's \xphi, in the High Level Trigger. These accelerators have the potential to provide faster or more energy efficient event selection, thus opening up possibilities for new complex triggers that were not previously feasible. At the same time, it is crucial to explore the performance limits achievable on the latest generation multicore CPUs with the use of the best software optimization methods. In this article, a new tracking algorithm based on the Hough transform will be evaluated for the first time on a multi-core Intel Xeon E5-2697v2 CPU, an NVIDIA Tesla K20c GPU, and an Intel \xphi\ 7120 coprocessor. Preliminary time performance will be presented.Comment: 13 pages, 4 figures, Accepted to JINS

    Leading Infrared Logarithms from Unitarity, Analyticity and Crossing

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    We derive non-linear recursion equations for the leading infrared logarithms in massless non-renormalizable effective field theories. The derivation is based solely on the requirements of the unitarity, analyticity and crossing symmetry of the amplitudes. That emphasizes the general nature of the corresponding equations. The derived equations allow one to compute leading infrared logarithms to essentially unlimited loop order without performing a loop calculation. For the implementation of the recursion equation one needs to calculate tree diagrams only. The application of the equation is demonstrated on several examples of effective field theories in four and higher space-time dimensions.Comment: 12 page

    Twist Deformation of the rank one Lie Superalgebra

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    The Drinfeld twist is applyed to deforme the rank one orthosymplectic Lie superalgebra osp(12)osp(1|2). The twist element is the same as for the sl(2)sl(2) Lie algebra due to the embedding of the sl(2)sl(2) into the superalgebra osp(12)osp(1|2). The R-matrix has the direct sum structure in the irreducible representations of osp(12)osp(1|2). The dual quantum group is defined using the FRT-formalism. It includes the Jordanian quantum group SLξ(2)SL_\xi(2) as subalgebra and Grassmann generators as well.Comment: LaTeX, 9 page

    Universal R-matrix for null-plane quantized Poincar{\'e} algebra

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    The universal R{\cal R}--matrix for a quantized Poincar{\'e} algebra P(3+1){\cal P}(3+1) introduced by Ballesteros et al is evaluated. The solution is obtained as a specific case of a formulated multidimensional generalization to the non-standard (Jordanian) quantization of sl(2)sl(2).Comment: 9 pages, LaTeX, no figures. The example on page 5 has been supplemented with the full descriptio
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