Nanoscopy of pairs of atoms by fluorescence in a magnetic field

Spontaneous emission spectra of two initially excited closely spaced identical atoms are very sensitive to the strength and the direction of the applied magnetic field. The relevant schemes are considered that ensure the determination of the mutual spatial orientation of the atoms and the distance between them by entirely optical means. A corresponding theoretical description is given accounting for the dipole-dipole interaction between the two atoms in the presence of a magnetic field and for polarizations of the quantum field interacting with magnetic sublevels of the two-atom system

Informational business activity: Features of pricing and transformations of a network effect

This paper is devoted to an analysis of the information which has become one of the leading economic resources defining the logic of macroeconomic dynamics and competitiveness of the national economy. The features of pricing in the market of information products, and network market transformation mechanism under the influence of digitalization, the problems and the negative consequences of the information economy, the need for a new understanding of the industry dynamics in the network sector, and the network effects which has a positive feedback are presented. Upon a high level of development of modern information technologies a consumer is able to make a choice between traditional and non-traditional ways of providing information. With the variety of types of information that is predetermined by a wide range of consumers of information products and services representing a consumer and industrial demand, the bulk of a company's information products is consumed today by enterprises, not by individual users. Each producer solves a number of issues in the process of formation of prices for information products and services taking into account solvency of consumers, the market structure of the product and so on often relying on the uniqueness of these products and services (for example, an advantage on the database market in determining the level price, of course, belongs to those are unique). Value of qualitatively different information products (associated with such properties as relevance, usefulness, completeness, timeliness, accessibility, submission form, reliability, and so on) determines extensive use of all available means for achieving flexible prices (negotiated prices, margins for the novelty, markdowns, discounts, price concessions, and others.)

Associations of Dwarf Galaxies

Hubble Space Telescope Advanced Cameras for Surveys has been used to determine accurate distances for 20 galaxies from measurements of the luminosity of the brightest red giant branch stars. Five associations of dwarf galaxies that had originally been identified based on strong correlations on the plane of the sky and in velocity are shown to be equally well correlated in distance. Two more associations with similar properties have been discovered. Another association is identified that is suggested to be unbound through tidal disruption. The associations have the spatial and kinematic properties expected of bound structures with 1 - 10 x 10^11 solar mass. However, these entities have little light with the consequence that mass-to-light ratios are in the range 100 - 1000 in solar units. Within a well surveyed volume extending to 3 Mpc, all but one known galaxy lies within one of the groups or associations that have been identified.Comment: 50 pages, 2 tables, 15 encapsulated figures, 1 (3 part) jpg figure. Submitted to Astronomical Journa