A lower bound for the size of the largest critical sets in Latin squares
arXiv:math/0701014
Abstract
A critical set in an array is a set of given entries, such that there exists a unique extension of to an Latin square and no proper subset of has this property. The cardinality of the largest critical set in any Latin square of order is denoted by $\lcs{n}$. We give a lower bound for $\lcs{n}$ by showing that $\lcs{n} \geq n^2(1-\frac{2 + \ln 2}{\ln n})+n(1+\frac {\ln (8 π)} {\ln n})-\frac{\ln 2}{\ln n}.$