3,399 research outputs found
Higher Spin Conformal Currents in Minkowski Space
Using unfolded formulation of free equations for massless fields of all spins
we obtain explicit form of higher-spin conformal conserved charges bilinear in
4d massless fields of arbitrary spins.Comment: LaTeX, 10 pages. Corrected typo
Cold Collision Frequency Shift in Two-Dimensional Atomic Hydrogen
We report a measurement of the cold collision frequency shift in atomic
hydrogen gas adsorbed on the surface of superfluid 4He at T<=90 mK. Using
two-photon electron and nuclear magnetic resonance in 4.6 T field we separate
the resonance line shifts due to the dipolar and exchange interactions, both
proportional to surface density sigma. We find the clock shift Delta v_c =
-1.0(1)x10^-7 Hz cm^-2 x sigma, which is about 100 times smaller than the value
predicted by the mean field theory and known scattering lengths in the 3D case.Comment: 4 pages, 3 figure
Master Higher-Spin Particle
We propose a "master" higher-spin (HS) particle system. The particle model
relevant to the unfolded formulation of HS theory, as well as the HS particle
model with a bosonic counterpart of supersymmetry, follow from the master model
as its two different gauges. Quantization of the master system gives rise to a
new form of the massless HS equations in an extended space involving, besides
extra spinorial coordinates, also a complex scalar one. As solutions to these
equations we recover the massless HS multiplet with fields of all integer and
half-integer helicities, and obtain new multiplets with a non-zero minimal
helicity. The HS multiplets are described by complex wave functions which are
holomorphic in the scalar coordinate and carry an extra U(1) charge q. The
latter fully characterizes the given multiplet by fixing the minimal helicity
as q/2. We construct a twistorial formulation of the master system and present
the general solution of the associate HS equations through an unconstrained
twistor "prepotential".Comment: 21 pages, minor corrections, version to appear in Class. Quantum Gra
BTZ Black Hole as Solution of 3d Higher Spin Gauge Theory
BTZ black hole is interpreted as exact solution of 3d higher spin gauge
theory. Solutions for free massless fields in BTZ black hole background are
constructed with the help of the star-product algebra formalism underlying the
formulation of 3d higher spin theory. It is shown that a part of higher spin
symmetries remains unbroken for special values of the BTZ parameters.Comment: 31 pages, LaTeX; references correcte
Dynamical lattice instability versus spin liquid state in a frustrated spin chain system
The low-dimensional s=1/2 compound (NO)[Cu(NO3)3] has recently been suggested
to follow the Nersesyan-Tsvelik model of coupled spin chains. Such a system
shows unbound spinon excitations and a resonating valence bond ground state due
spin frustration. Our Raman scattering study demonstrates phonon anomalies as
well as the suppression of a broad magnetic scattering continuum for
temperatures below a characteristic temperature, T<T*=100K. We interpret these
effects as evidence for a dynamical interplay of spin and lattice degrees of
freedom that might lead to a further transition into a dimerized or
structurally distorted phase at lower temperatures.Comment: 5 pages, 6 figure
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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