▎ 摘　　要

A recent measurement of the optical conductivity in graphene [Gallagher, Yang, Lyu, Tian, Kou, Zhang, Watanabe, Taniguchi, and Wang, Science 364, 158 (2019)] offers a possibility of experimental determination of microscopic time scales describing scattering processes in the electronic fluid. In this paper, I report a theoretical calculation of the optical conductivity in graphene at arbitrary doping levels, within the whole "hydrodynamic" temperature range, and for arbitrary nonquantizing magnetic fields. The obtained results are in good agreement with the available experimental data.