Using techniques similar to Gryzlov's, we prove that every 2κ-total, T1-space of pseudocharacter ⩽ κ is compact and hence of cardinality ⩽ 2κ. Some related results and examples are given.

We focus in this paper on the cardinality constrained mean-variance portfolio selection problem. Instead of tailoring such a difficult problem into the general solution framework of mixed-integer ...