
Differentiable mapping generated by elliptic paraboloid complexes
Author(s) -
Maksim Kretov
Publication year - 2020
Publication title -
differencialʹnaâ geometriâ mnogoobrazij figur
Language(s) - English
Resource type - Journals
eISSN - 2782-3229
pISSN - 0321-4796
DOI - 10.5922/0321-4796-2020-51-9
Subject(s) - paraboloid , mathematics , frenet–serret formulas , coordinate system , vertex (graph theory) , pure mathematics , tangent , mathematical analysis , geometry , combinatorics , surface (topology) , graph , curvature
In three-dimensional equiaffine space, we consider a differentiable map generated by complexes with three-parameter families of elliptic paraboloids according to the method proposed by the author in the materials of the international scientific conference on geometry and applications in Bulgaria in 1986, as well as in works published earlier in the scientific collection of Differ. Geom. Mnogoobr. Figur. The study is carried out in the canonical frame, the vertex of which coincides with the top of the generating element of the manifold, the first two coordinate vectors are conjugate and lie in the tangent plane of the elliptic paraboloid at its vertex, the third coordinate vector is directed along the main diameter of the generating element so that the ends are, respectively, the sums of the first and third, and also the sums of the second and third coordinate vectors lay on a paraboloid, while the indicatrixes of all three coordinate vectors describe lines with tangents, parallel to the first coordinate vector. The existence theorem of the mapping under study is proved, according to which it exists and is determined with the arbitrariness of one function of one argument. The systems of equations of the indicatrix and the main directions of the mapping under consideration are obtained. The indicatrix and the cone of the main directions of the indicated mapping are geometrically characterized.