English

Monochromatic Sums and Quotients Near Zero

Combinatorics 2026-04-23 v1

Abstract

Recently S. Goswami proved that whenever the set N\mathbb N of natural numbers is finitely colored, the set {a,b,ab,b(a+1)}\{a, b, ab, b(a+1)\} is monochromatic which also established a variant of the long-standing Hindman's conjecture, which asks for a monochromatic set of the form {a,b,ab,a+b}\{a, b, ab, a+b\}. Actually he disproved a conjecture proposed by J. Sahasrabudhe that {a,b,a(b+1)}\{a, b, a(b + 1)\} is not partition regular. In this paper we prove that {a,b,ab,b(a+1)}\{a, b, ab, b(a+1)\} is monochromatic near zero which means for every finite coloring of a dense subsemigroups of ((0,),+)((0, \infty), +), the set {a,b,ab,b(a+1)}\{a, b, ab, b(a+1)\} is monochromatic near zero or in other words, we will get a,ba, b in a dense subsemigroups of ((0,),+)((0, \infty), +) as small as we want such that the set {a,b,ab,b(a+1)}\{a, b, ab, b(a+1)\} is monochromatic for every finite coloring of that dense subsemigroups of ((0,),+)((0, \infty), +), also we show that the pattern x,y,x+y,yxx, y, x+y, \frac{y}{x} is partition regular near zero.

Keywords

Cite

@article{arxiv.2604.20106,
  title  = {Monochromatic Sums and Quotients Near Zero},
  author = {Md Moid Shaikh and Sourav Kanti Patra and Mukesh Kumar},
  journal= {arXiv preprint arXiv:2604.20106},
  year   = {2026}
}

Comments

10 pages

R2 v1 2026-07-01T12:29:35.524Z