8,690 research outputs found
Three-point correlation function of a scalar mixed by an almost smooth random velocity field
We demonstrate that if the exponent that measures non-smoothness of
the velocity field is small then the isotropic zero modes of the scalar's
triple correlation function have the scaling exponents proportional to
. Therefore, zero modes are subleading with respect to the
forced solution that has normal scaling with the exponent .Comment: 13 pages, RevTeX 3.
On the Fourier transform of the characteristic functions of domains with -smooth boundary
We consider domains with -smooth boundary and
study the following question: when the Fourier transform of the
characteristic function belongs to ?Comment: added two references; added footnotes on pages 6 and 1
Strong effect of weak diffusion on scalar turbulence at large scales
Passive scalar turbulence forced steadily is characterized by the velocity
correlation scale, , injection scale, , and diffusive scale, . The
scales are well separated if the diffusivity is small, , and one
normally says that effects of diffusion are confined to smaller scales, . However, if the velocity is single scale one finds that a weak dependence
of the scalar correlations on the molecular diffusivity persists to even larger
scales, e.g. \cite{95BCKL}. We consider the case of
and report a counter-intuitive result -- the emergence of a new range of large
scales, , where the diffusivity shows a strong effect on
scalar correlations.Comment: 4 pages, 1 figure, submitted to Physics of Fluid
Colour Coherence in Photon Induced Reactions
Colour coherence in hard photoproduction is considered using the Monte Carlo
event generators PYTHIA and HERWIG. Significant effects in the parton shower
are found using multijet observables for direct and resolved photon induced
reactions. The particle flow in the interjet region of direct processes shows a
strong influence of string fragmentation effects.Comment: 6 pages, LaTeX, 6 eps figures included, to appear in the proceedings
of the workshop "Future Physics at HERA
Solving the two-center nuclear shell-model problem with arbitrarily-orientated deformed potentials
A general new technique to solve the two-center problem with
arbitrarily-orientated deformed realistic potentials is demonstrated, which is
based on the powerful potential separable expansion method. As an example,
molecular single-particle spectra for C + C Mg are
calculated using deformed Woods-Saxon potentials. These clearly show that
non-axial symmetric configurations play a crucial role in molecular resonances
observed in reaction processes for this system at low energy
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