Mathematical Modeling in Problems of Homogeneous (Pseudo)Riemaimian Geometry

Currently, mathematical and computer modeling, as well as systems of symbolic calculations, are actively used in many areas of mathematics. Popular computer math systems as Maple, Mathematica, MathCad, MatLab allow not only to perform calculations using symbolic expressions but also solve algebraic and differential equations (numerically and analytically) and visualize the results. Differential geometry, like other areas of modern mathematics, uses new computer technologies to solve its own problems. The applying is not limited only to numerical calculations; more and more often, computer mathematics systems are used for analytical calculations. At the moment, there are many examples that prove the effectiveness of systems of analytical calculations in the proof of theorems of differential geometry.This paper demonstrates how symbolic computation packages can be used to classify neither conformally flat nor Ricci parallel four-dimensional Lie groups with leftinvariant (pseudo)Riemannian metric of the algebraic Ricci soliton with the zero Schouten-Weyl tensor.

New Dzungaria Gates for wmlt-corridor: historical necessity

Background: Research is ongoing relating to the analysis of a set of issues that arise in connection with the creation of the operating on the basis of vacuum magnetic technologies a transcontinental high-speed land transport corridor, connecting the eastern regions of China with Russia. As part of the variation calculus task, the geopolitical, economic, social, logistic, geographic, geomorphological, seismological, topographic components of the project are considered, in which it is assumed that the high speed overland route will pass through the north-western part of the historical region of Dzungaria. Aim: Find the most optimal from the point of view of the above components the location of the most important section of high speed overland route passing through Central Asia. Methods: Variational methods for solving an optimization problem with the use of a computer math system. Results: After creating a fairly informative and versatile picture of the region in question, the foundations of the corresponding mathematical models are built. Conclusion: The New Dzungarian Gates is a key element in choosing the location of a high-speed overland route based on VMLT.

ONE FEATURE OF THE CONSTRUCTIVE SOLUTIONS OF THE LATTICE GIRDER

The problem of the deflection of a planar symmetric statically determinable truss with a double lattice depending on the number of panels was solved in an analytical form. The angle of inclination of the ascending and descending rods of the truss is different. A load is applied to the truss, evenly distributed over the nodes of the lower chord. Special operators of the Maple computer math system and the induction method were used to generalize individual particular solutions to an arbitrary case. Formulas are obtained for the forces the most compressed and stretched truss rods. Cases of kinematic variability of the structure are revealed. A picture of the possible speeds of truss nodes in these cases is constructed. The asymptotic behavior of the deflection is found with a large number of panels and a fixed span length. The deflection was determined by the formula of Maxwell – Mohr.