Representation of Finite Abelian Group Elements by Subsequence Sums
| dc.creator | Grynkiewicz, D. J. | |
| dc.creator | Marchan, E. | |
| dc.creator | Ordaz, O. | |
| dc.date | 2008-06-02 | |
| dc.date.accessioned | 2026-07-07T09:42:14Z | |
| dc.date.available | 2026-07-07T09:42:14Z | |
| dc.description | Let $G\cong C_{n_1}\oplus ... \oplus C_{n_r}$ be a finite and nontrivial abelian group with $n_1|n_2|...|n_r$. A conjecture of Hamidoune says that if $W=w_1... w_n$ is a sequence of integers, all but at most one relatively prime to $|G|$, and $S$ is a sequence over $G$ with $|S|\geq |W|+|G|-1\geq |G|+1$, the maximum multiplicity of $S$ at most $|W|$, and $σ(W)\equiv 0\mod |G|$, then there exists a nontrivial subgroup $H$ such that every element $g\in H$ can be represented as a weighted subsequence sum of the form $g=\sum_{i=1}^{n}w_is_i$, with $s_1... s_n$ a subsequence of $S$. We give two examples showing this does not hold in general, and characterize the counterexamples for large $|W|\geq {1/2}|G|$. A theorem of Gao, generalizing an older result of Olson, says that if $G$ is a finite abelian group, and $S$ is a sequence over $G$ with $|S|\geq |G|+D(G)-1$, then either every element of $G$ can be represented as a $|G|$-term subsequence sum from $S$, or there exists a coset $g+H$ such that all but at most $|G/H|-2$ terms of $S$ are from $g+H$. We establish some very special cases in a weighted analog of this theorem conjectured by Ordaz and Quiroz, and some partial conclusions in the remaining cases, which imply a recent result of Ordaz and Quiroz. This is done, in part, by extending a weighted setpartition theorem of Grynkiewicz, which we then use to also improve the previously mentioned result of Gao by showing that the hypothesis $|S|\geq |G|+D(G)-1$ can be relaxed to $|S|\geq |G|+d^*(G)$, where $d^*(G)=\Sum_{i=1}^{r}(n_i-1)$. We also use this method to derive a variation on Hamidoune's conjecture valid when at least $d^*(G)$ of the $w_i$ are relatively prime to $|G|$. | |
| dc.identifier | https://arxiv.org/abs/0806.0309 | |
| dc.identifier | http://arxiv.org/abs/0806.0309 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/162107 | |
| dc.subject | Number Theory | |
| dc.subject | Combinatorics | |
| dc.subject | 11B75 (20K01) | |
| dc.title | Representation of Finite Abelian Group Elements by Subsequence Sums | |
| dc.type | text |