Weighted zero-sum constants and inverse results

Shruti S Hegde (Ramakrishna Mission Vivekananda Educational and Research Institute, India)

25-May-2022, 13:00-13:25 (4 years ago)

Abstract: A weighted generalization of classical zero-sum constants was introduced by Adhikari et al. in 2006 and has been an active area of research since then. In the last fifteen years, weighted zero-sum constants for $\mathbb {Z}_n$ with several interesting weight sets have been found. In this talk, we take up the problem of determining the exact values and providing bounds of weighted Davenport constant of $\mathbb {Z}_n$ with some new weight sets.

Next, we consider a weighted generalization of the Erd\H{o}s-Ginzburg-Ziv constant. Let $G$ be a finite abelian group with $\exp(G)=n$. For a positive integer $k$ and a non-empty subset $A$ of $[1, n-1]$, the arithmetical invariant $\mathsf s_{kn,A}(G)$ is defined to be the least positive integer $t$ such that any sequence of $t$ elements in $G$ has an $A$- weighted zero-sum subsequence of length $kn$. We give the exact value of $\mathsf s_{kq,A}(G)$, for integers $k\geq 2$ and $A=\{1,2\}$, when $G$ is an abelian $p$-group with $rank(G)\leq 4$, $p$ is an odd prime and $exp(G)=q$. Our method consists of a modification of a polynomial method of R\'onyai.

Lastly, we consider the questions regarding inverse problems for the weighted zero-sum constants of $\mathbb {Z}_n$. An inverse problem is a problem of characterizing all the weighted {\it zero-sum free sequences} over $\mathbb {Z}_n$ of specific lengths for the particular weight sets under consideration.

This work was joint with Sukumar Das Adhikari and partly with Md Ibrahim Molla and Subha Sarkar.

combinatorics

Audience: researchers in the discipline

( paper )


Combinatorial and additive number theory (CANT 2022)

Organizer: Mel Nathanson*
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