Jech–Kunen tree
In mathematics, a ω1-tree is a tree of power ω1 and height ω1. A Jech–Kunen tree is a ω1-tree in which the number of branches is greater than ω1 and less than 2ω1. It is named after who found the first model in which this tree exists, and who showed that, assuming the continuum hypothesis and 2ω1 > ω2, the existence of a Jech–Kunen tree is equivalent to the existence of a compact Hausdorff space with weight ω1 and cardinality strictly between ω1 and 2ω1.
