2,379 research outputs found
Dynamic speckle - Interferometry of micro-displacements
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
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
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
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
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
The Drinfeld twist is applyed to deforme the rank one orthosymplectic Lie
superalgebra . The twist element is the same as for the Lie
algebra due to the embedding of the into the superalgebra .
The R-matrix has the direct sum structure in the irreducible representations of
. The dual quantum group is defined using the FRT-formalism. It
includes the Jordanian quantum group as subalgebra and Grassmann
generators as well.Comment: LaTeX, 9 page
Universal R-matrix for null-plane quantized Poincar{\'e} algebra
The universal --matrix for a quantized Poincar{\'e} algebra 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 .Comment: 9 pages, LaTeX, no figures. The example on page 5 has been
supplemented with the full descriptio
- …