English

Bisecting and D-secting families for set systems

Combinatorics 2019-02-21 v3 Discrete Mathematics

Abstract

Let nn be any positive integer and F\mathcal{F} be a family of subsets of [n][n]. A family F\mathcal{F}' is said to be DD-\emph{secting} for F\mathcal{F} if for every AFA \in \mathcal{F}, there exists a subset AFA' \in \mathcal{F}' such that AAA([n]A)=i|A \cap A'| - |A \cap ([n] \setminus A')|=i, where iDi \in D, D{n,n+1,,0,,n}D \subseteq \{-n,-n+1,\ldots,0,\ldots,n\}. A DD-\emph{secting} family F\mathcal{F}' of F\mathcal{F}, where D={1,0,1}D=\{-1,0,1\}, is a \emph{bisecting} family ensuring the existence of a subset AFA' \in \mathcal{F}' such that AA{A2,A2}|A \cap A'| \in \{\lceil \frac{|A|}{2}\rceil,\lfloor \frac{|A|}{2}\rfloor\}, for each AFA \in \mathcal{F}. In this paper, we study DD-secting families for F\mathcal{F} with restrictions on DD, and the cardinalities of F\mathcal{F} and the subsets of F\mathcal{F}.

Keywords

Cite

@article{arxiv.1604.01482,
  title  = {Bisecting and D-secting families for set systems},
  author = {Niranjan Balachandran and Rogers Mathew and Tapas Kumar Mishra and Sudebkumar Prasant Pal},
  journal= {arXiv preprint arXiv:1604.01482},
  year   = {2019}
}

Comments

15 pages, text overlap with https://www.ams.org/journals/tran/1987-300-01/S0002-9947-1987-0871675-6/S0002-9947-1987-0871675-6.pdf in Theorem 7

R2 v1 2026-06-22T13:26:08.458Z