摘要
The main aim of this paper is to prove that the maximal operator σ# is not bounded from the martingale Hardy space Hp （G） to the martingale Hardy space Hp （G） for 0〈p≤1.
The main aim of this paper is to prove that the maximal operator σ# is not bounded from the martingale Hardy space Hp （G） to the martingale Hardy space Hp （G） for 0〈p≤1.
