Flag curvatures on Berwald submersions (Q2216936)

The O'Neill structural equations are well known as a very important tool in the study of Riemannian submersions. The goal of the paper under review is to establish similar relations in the framework of Berwald manifolds due to the similarities with the Riemannian setting. The main result proves that the flag curvature is nondecreasing on \(\pi\)-horizontal planes. A very interesting example concerning with a Lie group and a closed subgroup is included.