66 research outputs found
Features of Magneto-Optical Resonances in an Elliptically Polarized Traveling Light Wave
The parameters of nonlinear absorption magneto-optical resonances in the
Hanle configuration have been studied as functions of the ellipticity of a
traveling light wave. It has been found that these parameters (amplitude,
width, and amplitude-to-width ratio) depend strongly on the polarization of the
light wave. In particular, the resonance amplitude can increase by more than an
order of magnitude when the polarization changes from linear to optimal
elliptic. It has been shown that this effect is associated with the Doppler
frequency shift for atoms in a gas. The theoretical results have been
corroborated in experiments in Rb vapor.Comment: 5 page
Capillary wave turbulence on a spherical fluid surface in low gravity
We report the observation of capillary wave turbulence on the surface of a
fluid layer in a low-gravity environment. In such conditions, the fluid covers
all the internal surface of the spherical container which is submitted to
random forcing. The surface wave amplitude displays power-law spectrum over two
decades in frequency, corresponding to wavelength from to a few . This
spectrum is found in roughly good agreement with wave turbulence theory. Such a
large scale observation without gravity waves has never been reached during
ground experiments. When the forcing is periodic, two-dimensional spherical
patterns are observed on the fluid surface such as subharmonic stripes or
hexagons with wavelength satisfying the capillary wave dispersion relation
Weak Turbulent Kolmogorov Spectrum for Surface Gravity Waves
We study the long-time evolution of gravity waves on deep water exited by the
stochastic external force concentrated in moderately small wave numbers. We
numerically implement the primitive Euler equations for the potential flow of
an ideal fluid with free surface written in canonical variables, using
expansion of the Hamiltonian in powers of nonlinearity of up to fourth order
terms.
We show that due to nonlinear interaction processes a stationary energy
spectrum close to is formed. The observed spectrum can be
interpreted as a weak-turbulent Kolmogorov spectrum for a direct cascade of
energy.Comment: 4 pages, 5 figure
Form factors in the Bullough-Dodd related models: The Ising model in a magnetic field
We consider particular modification of the free-field representation of the
form factors in the Bullough-Dodd model. The two-particles minimal form factors
are excluded from the construction. As a consequence, we obtain convenient
representation for the multi-particle form factors, establish recurrence
relations between them and study their properties. The proposed construction is
used to obtain the free-field representation of the lightest particles form
factors in the perturbed minimal models. As a significant example
we consider the Ising model in a magnetic field. We check that the results
obtained in the framework of the proposed free-field representation are in
agreement with the corresponding results obtained by solving the bootstrap
equations.Comment: 20 pages; v2: some misprints, textual inaccuracies and references
corrected; some references and remarks adde
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