Wave scattering on a domain wall in a chain of PT-symmetric couplers

We study wave propagation in linear arrays composed of pairs of conjugate waveguides with balanced gain and loss, i.e. arrays of the PT-symmetric couplers, where the linear spectrum is known to feature high-frequency and low-frequency branches. We introduce a domain wall by switching the gain and loss in a half of the array, and analyze the scattering of linear waves on this defect. The analysis reveals two major effects: amplification of both reflected and transmitted waves, and excitation of the reflected and transmitted low-frequency and high-frequency waves by the incident high-frequency and low-frequency waves, respectively.Comment: 7 pages, 9 figures, Physical Review A, in pres

Exact Moving and Stationary Solutions of a Generalized Discrete Nonlinear Schrodinger Equation

We obtain exact moving and stationary, spatially periodic and localized solutions of a generalized discrete nonlinear Schr\"odinger equation. More specifically, we find two different moving periodic wave solutions and a localized moving pulse solution. We also address the problem of finding exact stationary solutions and, for a particular case of the model when stationary solutions can be expressed through the Jacobi elliptic functions, we present a two-point map from which all possible stationary solutions can be found. Numerically we demonstrate the generic stability of the stationary pulse solutions and also the robustness of moving pulses in long-term dynamics.Comment: 22 pages, 7 figures, to appear in J. Phys.

Optimizing the economic information transparency level of high-tech enterprises in the post-industrial globalized economy

Purpose: Managerial conditions of economic operation of a high technology enterprise as it integrates into the global economy that is essentially postindustrial and globalized were considered in this article. Design/Methodology/Approach: An inevitable immersion of the enterprise into the well-developed external infosphere, as well as a membrane borderline between the external and the internal infospheres were shown. The enterprise was represented dually – as both a donor and a recipient of information resources. Findings: An interpretation of the content of the infosphere was presented. Multiple causes of the discrete nature of the enterprise’s infosphere implementation were shown. The concept of “informational economic transparency” of an enterprise was introduced, and multiple components determining transparency levels were described. Practical Implications: The influence of transformations of informational economic transparency of an enterprise on external impacts on it from legal relations parties. Positive and negative effect of increases and decreases in the informational economic transparency of the enterprise were highlighted in the context of its influence on the economic counterpart and conflict-studies situations. The understanding of the specialized control object was provided. The optimizability of a level of the transparency in the aspect of target orientation of the enterprise was demonstrated. Originality/Value: A structural prototype to the primary support managerial toolkit in the shape of a DSS, a recommender system, allowing to conduct required feasibility studies of managerial decisions was proposed.peer-reviewe

Scattering of linear and nonlinear waves in a waveguide array with a PT -symmetric defect

We study the scattering of linear and nonlinear waves in a long waveguide array with a parity-time (PT)-symmetric defect created by two waveguides with balanced gain and loss. We present exact solutions for the scattering of linear waves on such a defect, and then demonstrate numerically that the linear theory can describe, with a good accuracy, the soliton scattering in the case of weak nonlinearity. We reveal that the reflected and transmitted linear and nonlinear waves can be amplified substantially after interaction with the PT-symmetric defect thus allowing an active control of the wave scattering in the array