Differential as a harmonic morphism with respect to Cheeger-Gromoll-type metrics (Q963259)

The horizontal conformality of a map between Riemannian manifolds, where the tangent bundles are equipped with Cheeger-Gromoll-type metrics, is investigated. The differential of the map is characterized as a harmonic morphism. See also \textit{S. Gudmundsson, E. Kappos}, [Tokyo J. Math. 25, No.~1, 75--83 (2002; Zbl 1019.53017)]; \textit{M. I. Munteanu}, Sci. Pap. Univ. Agric. Sci. Vet. Med., Fac. Hortic. 49, No.~2, 257--268 (2006; Zbl 1168.53309)]; \textit{M. Benyounes, E. Loubeau, C. M. Wood}, Differ. Geom. Appl. 25, No.~3, 322--334 (2007; Zbl 1128.53037)].