15,037 research outputs found
Closed-Form Approximation for Parallel-Plate Waveguide Coefficients
Simple closed-form formulas for calculating coefficients of modes excited in a parallel-plate waveguide illuminated by a planar wave are presented. The mode-matching technique and Green’s formula are used to arrive at a matrix-based expression for waveguide coefficients calculation. Simplified solution to this matrix is proposed to derive approximate mode coefficient formulas in closed-form for both TE and TM polarization. The results are validated by numerical simulations and show good accuracy for all incidence angles and in broad frequency range
Integral formulas for wave functions of quantum many-body problems and representations of gl(n)
We derive explicit integral formulas for eigenfunctions of quantum integrals
of the Calogero-Sutherland-Moser operator with trigonometric interaction
potential. In particular, we derive explicit formulas for Jack's symmetric
functions. To obtain such formulas, we use the representation of these
eigenfunctions by means of traces of intertwining operators between certain
modules over the Lie algebra , and the realization of these modules
on functions of many variables.Comment: 6 pages. One reference ([FF]) has been corrected. New references and
an introduction have been adde
Charged particle in higher dimensional weakly charged rotating black hole spacetime
We study charged particle motion in weakly charged higher dimensional black
holes. To describe the electromagnetic field we use a test field approximation
and use the higher dimensional Kerr-NUT-(A)dS metric as a background geometry.
It is shown that for a special configuration of the electromagnetic field the
equations of motion of charged particles are completely integrable. The vector
potential of such a field is proportional to one of the Killing vectors (called
primary Killing vector) from the `Killing tower' of symmetry generating objects
which exists in the background geometry. A free constant in the definition of
the adopted electromagnetic potential is proportional to the electric charge of
the higher dimensional black hole. The full set of independent conserved
quantities in involution is found. It is demonstrated, that Hamilton-Jacobi
equations are separable, as well as the corresponding Klein-Gordon equation and
its symmetry operators.Comment: 9 pages, no figure
A Lack of Resolved Near-Infrared Polarization Across the Face of M51
The galaxy M51 was observed using the Mimir instrument on the Perkins
telescope to constrain the resolved H-band (1.6 m) polarization across the
galaxy. These observations place an upper limit of on the -band
polarization across the face of M51, at 0.6 arcsecond pixel sampling. Even with
smoothing to coarser angular resolutions, to reduce polarization uncertainty,
the -band polarization remains undetected. The polarization upper limit at
-band, when combined with previous resolved optical polarimetry, rules out a
Serkowski-like polarization dependence on wavelength. Other polarization
mechanisms cannot account for the observed polarization ratio () across the face of M51.Comment: 4 pages, 2 figures, Accepted for publication in ApJ
A novel strong coupling expansion of the QCD Hamiltonian
Introducing an infinite spatial lattice with box length a, a systematic
expansion of the physical QCD Hamiltonian in \lambda = g^{-2/3} can be
obtained. The free part is the sum of the Hamiltonians of the quantum mechanics
of spatially constant fields for each box, and the interaction terms
proportional to \lambda^n contain n discretised spatial derivatives connecting
different boxes. As an example, the energy of the vacuum and the lowest scalar
glueball is calculated up to order \lambda^2 for the case of SU(2) Yang-Mills
theory.Comment: Talk given at the 6th International Workshop on "Critical Point and
Onset of Deconfinement (CPOD)", Dubna, Russia, 23-29 August 201
Numerical test for hyperbolicity of chaotic dynamics in time-delay systems
We develop a numerical test of hyperbolicity of chaotic dynamics in
time-delay systems. The test is based on the angle criterion and includes
computation of angle distributions between expanding, contracting and neutral
manifolds of trajectories on the attractor. Three examples are tested. For two
of them previously predicted hyperbolicity is confirmed. The third one provides
an example of a time-delay system with nonhyperbolic chaos.Comment: 7 pages, 5 figure
New Metrics Admitting the Principal Killing-Yano Tensor
It is believed that in any number of dimensions the off-shell Kerr-NUT-(A)dS
metric represents a unique geometry admitting the principal (rank 2,
non-degenerate, closed conformal Killing-Yano) tensor. The original proof
relied on the Euclidean signature and therein natural assumption that the
eigenvalues of the principal tensor have gradients of spacelike character. In
this paper we evade this common wisdom and construct new classes of Lorentzian
(and other signature) off-shell metrics admitting the principal tensor with
null eigenvalues, uncovering so a much richer structure of spacetimes with
principal tensor in four and higher dimensions. A few observations regarding
the Kerr-Schild ansatz are also made.Comment: 9 pages, no figures. v2: minor expansions, added reference
Quantum Computing, Metrology, and Imaging
Information science is entering into a new era in which certain subtleties of
quantum mechanics enables large enhancements in computational efficiency and
communication security. Naturally, precise control of quantum systems required
for the implementation of quantum information processing protocols implies
potential breakthoughs in other sciences and technologies. We discuss recent
developments in quantum control in optical systems and their applications in
metrology and imaging.Comment: 11 pages, 6 figures; Proceedings of SPIE: Fluctuations and Noise in
Photonics and Quantum Optics III (2005
Weakly charged generalized Kerr-NUT-(A)dS spacetimes
We find an explicit solution of the source free Maxwell equations in a
generalized Kerr-NUT-(A)dS spacetime in all dimensions. This solution is
obtained as a linear combination of the closed conformal Killing-Yano tensor
, which is present in such a spacetime, and a derivative of the primary
Killing vector, associated with . For the vanishing cosmological
constant the obtained solution reduces to the Wald's electromagnetic field
generated from the primary Killing vector.Comment: 4 pages, no figures v2: added reference
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