A zonotope is a linear image of the cube $[-1,1]^m$ for some $m \in \mathbb{N}$. We show that there is a universal constant $C$ such that, for every zonotope $Z\subset \mathbb{R}^d$ and vectors $v_1,\dots,v_n\in Z$, there are signs $x_1,\dots,x_n\in\{-1,1\}$ with \[ \sum_{i=1}^n x_i v_i \in C\sqrt d\, Z. \] This resolves a 2002 question of Schechtman and generalizes Spencer's six standard deviations theorem, which corresponds to the case $Z=[-1,1]^d$.
翻译:Zonotope是立方体 $[-1,1]^m$ 在线性映射下的像,其中 $m \in \mathbb{N}$。我们证明存在一个普适常数 $C$,使得对于任意Zonotope $Z\subset \mathbb{R}^d$ 及向量 $v_1,\dots,v_n\in Z$,总存在符号 $x_1,\dots,x_n\in\{-1,1\}$ 满足 \[ \sum_{i=1}^n x_i v_i \in C\sqrt d\, Z. \] 这一结果解决了Schechtman于2002年提出的问题,并推广了Spencer的六标准差定理(对应 $Z=[-1,1]^d$ 的情形)。