{ "id": "1505.01194", "version": "v1", "published": "2015-05-05T21:51:34.000Z", "updated": "2015-05-05T21:51:34.000Z", "title": "On the number of weighted subsequences with zero-sum in a finite abelian group", "authors": [ "AbĂ­lio Lemos", "Allan de Oliveira Moura" ], "comment": "arXiv admin note: text overlap with arXiv:1101.4492, arXiv:1308.3316 by other authors", "categories": [ "math.NT" ], "abstract": "Suppose $G$ is a finite abelian group and $S=g_{1}\\cdots g_{l}$ is a sequence of elements in $G$. For any element $g$ of $G$ and $A\\subseteq\\mathbb{Z}\\backslash\\left\\{ 0\\right\\} $, let $N_{A,g}(S)$ denote the number of subsequences $T=\\prod_{i\\in I}g_{i}$ of $S$ such that $\\sum_{i\\in I}a_{i}g_{i}=g$ , where $I\\subseteq\\left\\{ 1,\\ldots,l\\right\\}$ and $a_{i}\\in A$. The purpose of this paper is to investigate the lower bound for $N_{A,0}(S)$. In particular, we prove that $N_{A,0}(S)\\geq2^{|S|-D_{A}(G)+1}$, where $D_{A}(G)$ is the smallest positive integer $l$ such that every sequence over $G$ of length at least $l$ has a nonempty $A$-zero-sum subsequence. We also characterize the structures of the extremal sequences for which the equality holds for some groups.", "revisions": [ { "version": "v1", "updated": "2015-05-05T21:51:34.000Z" } ], "analyses": { "keywords": [ "finite abelian group", "weighted subsequences", "lower bound", "smallest positive integer", "zero-sum subsequence" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }