Additive Bases in Abelian Groups

Let $G$ be a finite, non-trivial abelian group of exponent $m$, and suppose that $B_1,\mathrm{.}\mathrm{.}\mathrm{.},B_k$ are generating subsets of $G$. We prove that if $k>2m \ln \log_2 |G|$,thenthemultisetunion$B_1\cup…\cup B_k$ forms an additive basis of $G$; that is, for every $g\in G$ there exist $A_1\subset B_1, …, A_k\subset B_k$suchthat$g=\sum_{i=1}^k\sum_{a\in A_i} a$. This generalizes a result of Alon, Linial, and Meshulam on the additive bases conjecture. As another step towards proving the conjecture, in the case where $B_1, …, B_k$ are finite subsets of a vector space we obtain lower-bound estimates for the number of distinct values, attained by the sums of the form $\sum_{i=1}^k \sum_{a\in A_i} a$,where$A_i$varyoverallsubsetsof$B_i$foreach$i=1,

…, k$. Finally, we establish a surprising relation between the additive bases conjecture and the problem of covering the vertices of a unit cube by translates of a lattice, and present a reformulation of (the strong form of) the conjecture in terms of coverings.