Where I can find a proof of the formula for Laplace-Beltrami operator for the Fubini-Study metric on $\mathbb{CP}^{n}$?
I've found this formula on page 8 in this work: https://arxiv.org/pdf/1602.06470v2.pdf .
Title of this work: ,,Stochastic areas, Winding numbers and Hopf fibrations".
Please help me with my problem.