On the Indicatrixes of Waves Scattering from the Random Fractal Anisotropic Surface

Millimeter and centimeter wave scattering from the random fractal anisotropic surface has been theoretically investigated. Designing of such surfaces is based on the modifications of non-differentiable two-dimensional Weierstrass function. Wave scattering on a random surface is interesting for many sections of physics, mathematics, biology, and so on. Questions of a radar location and radio physics take the predominating position here. There are many real surfaces and volumes in the nature that can be carried to fractal objects. At the same time, the description of processes of waves scattering of fractal objects differs from classical approaches markedly. There are many monographs in the world on the topic of classical methods of wave scattering but the number of books devoted to waves scattering on fractal stochastic surfaces is not enough. These results of estimation of three-dimensional scattering functions are a priority in the world and are important in radar of low-contrast targets near the surface of the earth and the sea

Revisiting perfect fluid dark matter: Observational constraints from our galaxy

We revisit certain features of an assumed spherically symmetric perfect fluid dark matter halo in the light of the observed data of our galax

Reciprocal Relations in Oscillations of Dissipative Systems

AbstractThe equations of the dynamic response of discrete dissipative systems at arbitrary load are considered within the theory of time analysis. The structure of the kinematic parameters of a reaction is analyzed and it is shown that the constituent matrices of movements, velocities and accelerations of the nodes of the system are symmetrical which is considered as a specific case of reciprocal relations in an elastic dissipative system. On the basis of the properties of matrices, the more general reciprocal relations are proved, where in addition to the familiar principle of reciprocity of virtual work there are reciprocal relations in the form of a product of mass forces and velocities and in the form of a product of mass forces and accelerations. The theoretical calculations are illustrated by the example