On the first secondary invariant of Molino's central sheaf
Tom 64 / 1996
Annales Polonici Mathematici 64 (1996), 253-265
DOI: 10.4064/ap-64-3-253-265
Streszczenie
For a Riemannian foliation on a closed manifold, the first secondary invariant of Molino's central sheaf is an obstruction to tautness. Another obstruction is the class defined by the basic component of the mean curvature with respect to some metric. Both obstructions are proved to be the same up to a constant, and other geometric properties are also proved to be equivalent to tautness.
