Measurable Cardinals and the Cardinality of Lindelöf Spaces
We obtain from the consistency of the existence of a measurable cardinal the consistency of "small" upper bounds on the cardinality of a large class of Lindelöf spaces whose singletons are G δ sets.
Scheepers, Marion. (2010). "Measurable Cardinals and the Cardinality of Lindelöf Spaces". Topology and its Applications, 157(9), 1651-1657. http://dx.doi.org/10.1016/j.topol.2010.03.004