Goncharova O. Pseudospherical and ruled submanifolds of Euclidean space

Isometric immersions of domains of Lobachevsky space into the Euclidean space, ruled surfaces in E^n, Gaussian torsion of ruled surfaces in E^4. The construction of new isometric immersions of Lobachevsky space into the Euclidean space, an analyze of ruled submanifolds in with zero Gaussian torsion. Methods of differential geometry and differential equation, methods of Rimanian geometry. A method is given to construct isometric immersions of domains of Lobachevsky space into the Euclidean space; an immersion is constructed in the form of the suspension over Veroneze surface and in the form of the suspension over do Carmo - Wallach minimal submanifolds; the curvature tensor of the normal connection of this immersion is computed; the total Gauss curvature of the complete regular orientable ruled surface is calculated; uniqueness theorems about ruled complete surfaces with zero Gaussian torsion are proved; standard ruled surfaces in E^n is introduced and investigated. The results are important for investigations of differential geometry of submanifolds.