4,160 research outputs found
Mixed-symmetry massless gauge fields in AdS(5)
Free AdS(5) mixed-symmetry massless bosonic and fermionic gauge fields of
arbitrary spins are described by using su(2,2) spinor language. Manifestly
covariant action functionals are constructed and field equations are derived.Comment: 13 pages; v2: title changed, typos corrected, minor changes,
reference added; v3: minor changes, published versio
Tunable Integrated-Optics Nanoscaled Devices Based on Magnetic Photonic Crystals
Magnetooptical properties of magnetic photonic crystals have been
investigated in the view of their possible applications for the modern
integrated-optics devices. A "transfer matrices" formalism was expanded for the
case of oblique light incidence on the periodic nanoscaled magnetic
multilayered systems. Several new effects such as the Faraday effect dependence
on the incidence angle and the tunability of the bandgap defect modes spectral
location by external magnetic fields were found. Several possibilities of
one-dimensional magnetic photonic crystals applications for the optical devices
are discussed. Initial steps towards the practical implementation of the
proposed devices are reported.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Higher Spin Gravitational Couplings and the Yang--Mills Detour Complex
Gravitational interactions of higher spin fields are generically plagued by
inconsistencies. We present a simple framework that couples higher spins to a
broad class of gravitational backgrounds (including Ricci flat and Einstein)
consistently at the classical level. The model is the simplest example of a
Yang--Mills detour complex, which recently has been applied in the mathematical
setting of conformal geometry. An analysis of asymptotic scattering states
about the trivial field theory vacuum in the simplest version of the theory
yields a rich spectrum marred by negative norm excitations. The result is a
theory of a physical massless graviton, scalar field, and massive vector along
with a degenerate pair of zero norm photon excitations. Coherent states of the
unstable sector of the model do have positive norms, but their evolution is no
longer unitary and their amplitudes grow with time. The model is of
considerable interest for braneworld scenarios and ghost condensation models,
and invariant theory.Comment: 19 pages LaTe
The steppe elephant Mammuthus trogontherii (Pohlig) from the Irtysh region near Omsk
A Pleistocene elephant skeleton was found in 1989 in the alluvial beds of the Tobolsk age on the Om River near the village of Ust’-Tarka (Ust’-Tarkskii District, Novosibirsk Region). The forelimbs and some thoracic and caudal vertebrae are not preserved. Judging from the heavy wear of M3/m3, this animal was about 50–60 years of individual age. The skeleton is about 3.5 m high at the withers. The geological age of the beds enclosing the skeleton and its morphological features suggest that it should be assigned to Mammuthus trogontherii
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