Periodica Mathematica Hungarica, cilt.80, sa.2, ss.249-258, 2020 (SCI-Expanded)
© 2020, Akadémiai Kiadó, Budapest, Hungary.The high-dimensional version of Fatou’s classical theorem asserts that the Poisson semigroup of a function f∈Lp(Rn),1≤p≤∞, converges to f non-tangentially at Lebesque points. In this paper we investigate the rate of non-tangential convergence of Poisson and metaharmonic semigroups at μ-smoothness points of f.