We obtain Marcinkiewicz--ygmund (MZ) inequalities in various Banach and quasi-Banach spaces under minimal assumptions on the structural properties of these spaces. Our main results show that the Bernstein inequality in a general quasi-Banach function lattice $X$ implies Marcinkiewicz-Zygmund type estimates in $X$. We present a general approach to obtain MZ inequalities not only for polynomials but for other function classes including entire functions of exponential type, splines, exponential sums, etc.
翻译:我们在各类Banach空间与拟Banach空间中,以关于这些空间结构性质的最小假设为前提,获得了Marcinkiewicz-Zygmund(MZ)不等式。我们的主要结果表明,在一般拟Banach函数格$X$中的Bernstein不等式蕴含着$X$中的Marcinkiewicz-Zygmund型估计。我们提出了一种通用方法,不仅可针对多项式,还可针对其他函数类(包括指数型整函数、样条函数、指数和等)获得MZ不等式。