“…where ω 1,2 are the angular frequencies of oscillations, G 1,2 are 2πperiodic in both argument functions, Δ is the time shift between the time series of φ 1 (t) and φ 2 (t), and ξ 1,2 (t) are Gaussian white noises with zero mean (Smirnov et al, 2011;Sidak et al, 2017). Increments of phases during some fixed time interval τ can be estimated from experimental time series as follows:…”