Pinning Down versus Density

István Juhász, Lajos Soukup, Zoltán Szentmiklóssy

The pinning down number $pd(X)$ of a topological space $X$ is the smallest cardinal $\kappa$ such that for any neighborhood assignment $U:X\to {\tau }_X$ there is a set $A\in [X{]}^{\kappa }$ with $…