On the Fano Variety of a Class of Real Four-Dimensional Cubics

The topological type of the real part of the Fano variety parametrizing the set of lines on a nonsingular real hypersurface of degree three in a five-dimensional projective space is evaluated provided that the hypersurface belongs to a special rigid projective class. In the paper by Finashin and Kharlamov on the rigid projective classification of real four-dimensional cubics, this class is said to be irregular. The results of the author of the present paper from the article devoted to the equivariant topological classification of the Fano varieties of real cubic fourfolds are also used.