Title
Forbidden Subposet Problems for Traces of Set Families.
Abstract
In this paper we introduce a problem that bridges forbidden subposet and forbidden subconfiguration problems. The sets F-1, F-2 , . . . , F-vertical bar p vertical bar form a copy of a poset P, if there exists a bijection i : P -> {F-1, F-2 , . . , F-vertical bar p vertical bar} such that for any p, p'is an element of P the relation p < p p' implies i(p) not subset of i(p'). A family F of sets is P -free if it does not contain any copy of P. The trace of a family F on a sets X is F vertical bar( X) := { F boolean AND X : F is an element of F}. We introduce the following notions: F subset of 2([n]) is l-trace P-free if for any l-subset L subset of [n], the family F vertical bar vertical bar (L) is P-free and F is trace P -free if it is l-trace P-free for all l <= n. As the first instances of these problems we determine the maximum size of trace B-free families, where B is the butterfly poset on four elements a, b, c, d with a, b < c, d and determine the asymptotics of the maximum size of (n - i)-trace K-r,K- (s)-free families for i = 1, 2. We also propose a generalization of the main conjecture of the area of forbidden subposet problems.
Year
Venue
Field
2018
ELECTRONIC JOURNAL OF COMBINATORICS
Discrete mathematics,Combinatorics,Bijection,Conjecture,Mathematics,Partially ordered set
DocType
Volume
Issue
Journal
25
3.0
ISSN
Citations 
PageRank 
1077-8926
0
0.34
References 
Authors
0
3
Name
Order
Citations
PageRank
Dániel Gerbner14621.61
Balázs Patkós28521.60
Máté Vizer32714.06