English

Weak multiset sequenceability and weak BHR conjecture

Combinatorics 2024-03-12 v1

Abstract

A subset SS of a group (G,+)(G,+) is tt-weakly sequenceable if there is an ordering (y1,,yk)(y_1, \ldots, y_k) of its elements such that the partial sums~s0,s1,,sks_0, s_1, \ldots, s_k, given by s0=0s_0 = 0 and si=j=1iyjs_i = \sum_{j=1}^i y_j for 1ik1 \leq i \leq k, satisfy sisjs_i \neq s_j whenever and 1ijt1 \leq |i-j|\leq t. In this paper, we consider the weak sequenceability problem on multisets. In particular, we are able to prove that a multiset M=[a1λ1,a2λ2,,anλn]M=[a_1^{\lambda_1},a_2^{\lambda_2},\dots,a_n^{\lambda_n}] of non-identity elements of a generic group GG is tt-weakly sequenceable whenever the underlying set {a1,a2,,an}\{a_1,a_2,\dots,a_n\} is sufficiently large (with respect to tt) and the smallest prime divisor pp of G|G| is larger than tt. A related question is the one posed by the Buratti, Horak, and Rosa (briefly BHR) conjecture here considered again in the weak sense. Given a multiset MM and a walk WW in Cay[G:±M]Cay[G: \pm M], we say that WW is a realization of MM if Δ(W)=±M\Delta(W)=\pm M. Here we prove that a multiset M=[a1λ1,a2λ2,,anλn]M=[a_1^{\lambda_1},a_2^{\lambda_2},\dots,a_n^{\lambda_n}] of non-identity elements of GG admits a realization W=(w0,,w)W=(w_0,\dots,w_{\ell}) such that wiwjw_i\neq w_j whenever and 1ijt1 \leq |i-j|\leq t assuming that M=λ1+λ2++λn|M|=\lambda_1+\lambda_2+\dots+\lambda_n is sufficiently large and the smallest prime divisor pp of G|G| is larger than t(2t+1)t(2t+1).

Keywords

Cite

@article{arxiv.2403.06781,
  title  = {Weak multiset sequenceability and weak BHR conjecture},
  author = {Simone Costa},
  journal= {arXiv preprint arXiv:2403.06781},
  year   = {2024}
}

Comments

arXiv admin note: text overlap with arXiv:2306.02721

R2 v1 2026-06-28T15:15:51.975Z