Is every Riemannian submersion necessarily a Harmonic map? If not under what condition that is true?
The motivation: the linear part of a Riemannian submersion is the direct sum og an isometry and the zero operator
I just realize that the answer is negative:
We give two conditions each one necessary and sufficient for a Riemannian submersion to be harmonic. As an application, we show how it can be modified the metric on the total space such that the Riemannian submersion to become harmonic.