二元格拉斯曼方案的FKN定理
An FKN Theorem for the Binary Grassmann Scheme
AI总结:
本文将Friedgut等提出的FKN定理推广到二元格拉斯曼方案,证明了该方案中与1次函数接近的二元函数的结构性质,为相关组合分析提供了新结果。
AI中文摘要:
Friedgut、Kalai和Naor提出的经典定理指出,若函数f∶{0,1}^n→{-1,1}与1次函数接近,则f或-f会接近全1函数,或接近(-1)^{x_i}(i∈[n])。本文针对有限域F₂上的格拉斯曼方案证明了该定理的一个版本,具体而言,若函数f∶[F₂ⁿ;ℓ]→{0,1}与1次函数接近,则f或1-f必须接近形如g(L)=∑_{x∈X}1_{x∈L}+∑_{W∈W}1_{L⊆W}的函数,其中X⊆F₂ⁿ是点集,W是F₂ⁿ中的超平面集。
英文摘要:
A classical theorem due to Friedgut, Kalai and Naor asserts that if a function $f\colon \{0,1\}^n\to\{-1,1\}$ close to a degree $1$ function, then either $f$ or $-f$ is close to either the all $1$ function, or to $(-1)^{x_i}$ for some $i\in [n]$. We prove a version of their theorem for the Grassmann scheme over $\mathbb{F}_2$. More precisely, we prove if a function $f\colon \genfrac{[}{]}{0pt}{}{\mathbb{F}_2^n}{\ell}\to\{0,1\}$ is close to a degree $1$ function, then either $f$ or $1-f$ must be close to a function of the form $g(L) = \sum_{x\in\mathcal{X}}1_{x\in L}+\sum_{W\in\mathcal{W}}1_{L\subseteq W}$, where $\mathcal{X}\subseteq\mathbb{F}_2^n$ is a set of points and $\mathcal{W}$ is a set of hyperplanes in $\mathbb{F}_2^n$.