Burban I. M.
Ukr. Mat. Zh. - 2005. - 57, № 1. - pp. 18–31
We discuss a categorical approach to the investigation of topological D-branes. Twist functors and their induced action on the cohomology ring of a manifold are studied. A nontrivial spherical object of the derived category of coherent sheaves of a reduced plane singular curve of degree 3 is constructed.
Ukr. Mat. Zh. - 1974. - 26, № 1. - pp. 67–70