Alpha-effect in three-dimensional coherent vortex of conducting rotating liquid

We study one-point statistics of spiral turbulent pulsations on the background of three-dimensional large-scale vortex in a rotating fluid. Assuming that the helical flow is created by a statistically axially symmetric random force with broken mirror symmetry, we analytically calculate velocity-vorticity mean including its magnitude and the anisotropy. For electrically conducting liquid, we examine the $\alpha$-effect in the system. The found elements of $\alpha$-matrix strongly depend on relation between Rossby $\mathrm{Ro}$ and magnetic Prandtl $\mathrm{Pr}_{\mathrm{m}}$ numbers in considered region $\mathrm{Ro}\lesssim 1$, $\mathrm{Pr}_{\mathrm{m}} \lesssim 1$. We establish criterion for the numbers when the $\alpha$-effect leads to instability of large-scale magnetic fieldComment: 16 page

Spatial statistics of passive scalar in two-dimensional shear flow with fluctuations

We examine statistical properties of the passive scalar field advected by the flow consisting of the regular shear flow and of irregular flow fluctuations. We consider the particular case of two-dimensional flow where the shear flow is dominating and the random flow is smooth. We examine both the decaying case and the case of the permanent supply of the passive scalar fluctuations. In both cases the passive scalar possesses strong intermittence, that can be characterized via the single-point moments and correlation functions, calculated in our work. We reveal features of the correlation functions related to the strong anisotropy of the flow. Our qualitative results are universal. Some quantitative results are obtained in the framework of the model where the flow fluctuations are short correlated in time.Comment: 14 pages, 2 figure

Identifying Extreme PAPR in Coherent Optical Communications

We apply well established concepts of adaptive wave front shaping used in imaging through turbid medium to detect detrimental phase modulated sequences in multi-carrier optical communications that can cause extreme power fluctuations due to dispersion enhanced interference of information symbols

Localized surface plasmon modes in a system of two interacting metallic cylinders

We study an optical response of a system of two parallel close metallic cylinders having nanoscale dimensions. Surface plasmon excitation in the gap between the cylinders is specifically analyzed. In particular, resonance frequencies and field enhancement were investigated as functions of geometrical characteristics of the system and ohmic losses in the metal. The results of numerical simulations were systematically compared with the analytical theory, obtained in the quasi-static limit. The analytical method was generalized in order to take into account the retardation effects. We also present the physical qualitative picture of the plasmon modes, which is validated by numerical simulations and analytical theory

Localized surface plasmon modes in a system of two interacting metallic cylinders

We study an optical response of a system of two parallel close metallic cylinders having nanoscale dimensions. Surface plasmon excitation in the gap between the cylinders are specifically analyzed. In particular, resonance frequencies and field enhancement were investigated as functions of geometrical characteristics of the system and Ohmic losses in the metal. The results of numerical simulations were systematically compared with the analytical theory, obtained in the quasi-static limit. The analytical method was generalized in order to take into account the retardation effects. We also present the physical qualitative picture of the plasmon modes, which is validated by numerical simulations and analytical theory