What are the left-handed media and what is interesting about them?

We review the intensively discussed ideas about wave propagation and refraction in media where both electric permittivity and magnetic permeability are negative. The criticism against negative refraction as violating the causality principle is considered. Starting from the initial wave equations, refraction of beams at the boundary of a left-handed medium is analyzed. The physics of a perfect lens formed by a flat layer of a left-handed material is considered.Comment: 21 pages, 8 figure

Few-Nucleon Systems: Notes about the Status and Results of Investigations

Radiation technologies have found wide application in power engineering, medicine, biology and other areas of human activities. However, theoretical calculations of nuclear reactions and, correspondingly, the interpretation of experimental results appear model-dependent. The model-independent calculation of the nuclear reaction must take into account the structure of the nuclear ground state, the final-state nucleon interaction and the contribution of meson exchange currents. These calculations can be carried out only with due regard for realistic NN and 3N forces between nucleons and also, with the use of exact methods of solving the many-body problem. In this technique it is expedient to conduct investigations of nuclear reactions as from few-nucleon systems in the energy area of the particles below the meson-producing threshold. The tensor part of NN interaction and 3NF,s generate the lightest nuclei states with nonzero orbital momenta of nucleons. These states in the lightest nuclei is conditioned the properties of inter-nucleonic forces, and therefore, similar effects should be observed unexceptionally in all nuclei. The review papers are generally devoted to three-nucleon systems. In this paper primary attention is given to the investigation of the $^4$He nucleus

Parametrization of U(N)-monopoles on black holes by the moduli space of holomorphic vector bundles over two-sphere and black hole entropy

We discuss how to describe U(N)-monopoles on the Schwarzschild and Reissner-Nordstr\"om black holes by the parameters of the moduli space of holomorphic vector bundles over S^2. For N = 2,3 we obtain such a description in an explicit form as well as the expressions for the corresponding monopole masses. This gives a possibility to adduce some reasonings in favour of existence of both a 'fine structure' for black holes and the statistical ensemble tied with it which might generate the black hole entropy. Also there arises some analogy with the famous K-theory in topology.Comment: 19 pages, LaTeX, minor modifications for correspondence to the published versio

Dirac equation in the confining SU(3)-Yang-Mills field and relativistic effects in charmonium spectrum

The recently obtained solutions of the Dirac equation in the confining SU(3)-Yang-Mills field in Minkowski spacetime are applied to describe the energy spectrum of charmonium. The nonrelativistic limit is considered for the relativistic effects to be estimated in a self-consistent way and it is shown that the given effects could be extremely important for both the energy spectrum and the confinement mechanism.Comment: 9 pages,LaTe