Massive scalar field in de Sitter spacetime: a two-loop calculation and a comparison with the stochastic approachAlexander Yu. Kamenshchik, Alexei A. Starobinsky and Tereza VardanyanEur. Phys. J. C, 82 4 (2022) 345DOI: https://doi.org/10.1140/epjc/s10052-022-10295-z