We study the decay dynamics of a two-level giant atom that is coupled to waveguide with time-dependent coupling strengths. In non-Markovian regime where retardation effect cannot be ignored, we show depends on atom-waveguide strengths at an earlier time. This allows one tailor and even realize stationary population revival appropriate modulations. Moreover, demonstrate possibility simulating qu...

Aims. In this paper, we aim to study the time dependence of sunspot group areas in a large sample composed various databases spanning over 130 years, used state-of-the-art statistical methods. Methods. For carefully selected but unbiased sample, use Bayesian modelling fit temporal evolution combined umbral and penumbral area spot groups with skew-normal function determine existence any asymmetr...