Copyright © 2013 V. N. Grebenev et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
The extended symmetry of the functional of length
determined in an affine space of the correlation vectors for
homogeneous isotropic turbulence is studied. The two-point velocity-correlation tensor field (parametrized by the time variable )
of the velocity fluctuations is used to equip this space by a
family of the pseudo-Riemannian metrics (Grebenev and Oberlack (2011)). First, we observe the results obtained by Grebenev and Oberlack (2011) and Grebenev et al. (2012) about a geometry of the correlation space and expose the Lie
algebra associated with the equivalence transformation of the
above-mentioned functional for the quadratic form
generated by which is similar to the Lie algebra
constructed by Grebenev et al. (2012). Then, using the properties of this
Lie algebra, we show that there exists a nontrivial central
extension wherein the central charge is defined by the same
bilinear skew-symmetric form as for the Witt algebra which
measures the number of internal degrees of freedom of the system.
For the applications in turbulence, as the main result, we
establish the asymptotic expansion of the transversal correlation
function for large correlation distances in the frame of
.