论文标题
用于$ a(a + a)$的新键
A new bound for $A(A + A)$ for large sets
论文作者
论文摘要
对于$ p $,是一个大码数,$ a \ subset \ mathbb {f} _p $我们证明以下内容: $(i)$如果$ a(a+a)$不能覆盖$ \ mathbb {f} _p $,然后$ | a |中的所有非零残基<p/8 + o(p)$。 $(ii)$如果$ a $既是无价值又满足$ a = a^*$,则$ | a | <p/9 + o(p)$。 $(iii)$如果$ | a | \ gg \ frac {\ log \ log {p}} {\ sqrt {\ log {p}}}} p $,然后$ | a + a + a^*| \ geqslant(1 -o(1))\ min(2 \ sqrt {| a | p},p)$。 在这里,常数$ 1/8 $,$ 1/9 $和$ 2 $是最好的。证明涉及\ emph {包装器},这是有限的Abelian Group $ G $的子集,我们在卷积中使用了$ a * b $的流行价值,用于密集集$ a,b \ subseteq g $。这些物体具有一些特殊的结构特征,使它们能够解决添加剂组合和枚举问题。
For $p$ being a large prime number, and $A \subset \mathbb{F}_p$ we prove the following: $(i)$ If $A(A+A)$ does not cover all nonzero residues in $\mathbb{F}_p$, then $|A| < p/8 + o(p)$. $(ii)$ If $A$ is both sum-free and satisfies $A = A^*$, then $|A| < p/9 + o(p)$. $(iii)$ If $|A| \gg \frac{\log\log{p}}{\sqrt{\log{p}}}p$, then $|A + A^*| \geqslant (1 - o(1))\min(2\sqrt{|A|p}, p)$. Here the constants $1/8$, $1/9$, and $2$ are the best possible. The proof involves \emph{wrappers}, subsets of a finite abelian group $G$, with which we `wrap' popular values in convolutions $A * B$ for dense sets $A, B \subseteq G$. These objects carry some special structural features, making them capable of addressing both additive-combinatorial and enumerative problems.