Abstract:
The aim of this paper is to define the $r$th Tachibana number $t_r$ of an $n$-dimensional compact oriented Riemannian manifold as the dimension of the space of conformally Killing $r$-forms, for $r=1,2,\dots,n-1$. We also describe properties of these numbers, by analogy with properties of the Betti numbers $b_r$ of a compact oriented Riemannian manifold.
Bibliography: 25 titles.