摘要
In this paper, we study the John-Nirenberg inequality for and the atomic decomposition for of noncommutative martingales. We first establish a crude version of the column (resp. row) John-Nirenberg inequality for all . By an extreme point property of -space for , we then obtain a fine version of this inequality. The latter corresponds exactly to the classical John-Nirenberg inequality and enables us to obtain an exponential integrability inequality like in the classical case. These results extend and improve Junge and Musat始s John-Nirenberg inequality. By duality, we obtain the corresponding q-atomic decomposition for different Hardy spaces for all , which extends the 2-atomic decomposition previously obtained by Bekjan et al. Finally, we give a negative answer to a question posed by Junge and Musat about .