English

On determination of Zero-sum $\ell$-generalized Schur Numbers for some linear equations

Combinatorics 2018-08-28 v1

Abstract

Let rr, mm and k2k\geq 2 be positive integers such that rkr\mid k and let v[0,k12r]v \in \left[ 0,\lfloor \frac{k-1}{2r} \rfloor \right] be any integer. For any integer [1,k]\ell \in [1, k] and ϵ{0,1}\epsilon \in \{0,1\}, we let Ev(,ϵ)\mathcal{E}_{v}^{(\ell, \epsilon)} be the linear homogeneous equation defined by Ev(,ϵ):x1++xk(rv+ϵ)=xk(rv+ϵ1)++xk\mathcal{E}_{v}^{(\ell, \epsilon)}: x_1 + \cdots + x_{k-(rv+\epsilon)} =x_{k-(rv+\epsilon-1)} +\cdots+ \ell x_{k}. We denote the number Sz,m(,ϵ)(k;r;v)S_{\mathfrak{z},m}^{(\ell, \epsilon)}(k;r;v), which is defined to be the least positive integer tt such that for any mm-coloring χ:[1,t]{0,1,,m1}\chi: [1, t] \to \{0, 1,\ldots,m-1\}, there exists a solution (x^1,x^2,,x^k)(\hat{x}_1, \hat{x}_2, \ldots, \hat{x}_k) to the equation Ev(,ϵ)\mathcal{E}_{v}^{(\ell,\epsilon)} that satisfies the rr-zero-sum condition, namely, i=1kχ(x^i)0(modr)\displaystyle\sum_{i=1}^k\chi(\hat{x}_i) \equiv 0\pmod{r}. In this article, we completely determine the constant Sz,2(k,1)(k;r;0)S_{\mathfrak{z}, 2}^{(k,1)}(k;r;0), Sz,m(k1,1)(k;r;0)S_{\mathfrak{z}, m}^{(k-1,1)}(k;r;0), Sz,2(1,1)(k;2;1)S_{\mathfrak{z}, 2}^{(1,1)}(k;2;1) and Sz,r(1,0)(k;r;v)S_{\mathfrak{z}, r}^{(1,0)}(k;r;v). Also, we prove upper bound for the constants Sz,2(2,1)(k;2;0)S_{\mathfrak{z},2}^{(2,1)}(k;2;0) and Sz,2(1,1)(k;2;v)S_{\mathfrak{z},2}^{(1,1)}(k;2;v).

Keywords

Cite

@article{arxiv.1808.08725,
  title  = {On determination of Zero-sum $\ell$-generalized Schur Numbers for some linear equations},
  author = {Bidisha Roy and Subha Sarkar},
  journal= {arXiv preprint arXiv:1808.08725},
  year   = {2018}
}