Products of Lindelöf spaces with points $G_{\delta }$

Abstract

We show that if CH holds and either (i) there exists an ${\omega }_1$-Kurepa tree, or (ii) $\square ({\omega }_2)$ holds, then there are regular $T_1$ Lindelöf spaces $X_0$ and $X_1$ with points $G_{\delta }$ such that $e(X_0\times X_1)>2^{\omega }$.