On the class of NY compact spaces of finitely supported elements and related classes

A compact space K is NY compact (ω-Corson) if K embeds into a σ-product of compact metrizable spaces (σ-product of intervals).  A combination of these definitions with a classical notion of a Valdivia compact space gives classes of NY-Valdivia and ω-Valdivia compacta. We provide an example of a uniform Eberlein compact space which is not  NY-Valdivia compact. This answers a question of Kubiś and Leiderman and a recent question of Hajek and Russo. Our example makes use of a new internal characterization of the class of NY-compacta, that enables us to identify all compacta whose Alexandroff duplicate is NY-Valdivia. A similar result concerning Alexandroff duplicates is also proved for the class of so-called semi-Eberlein compact spaces. This gives a wealth of examples of Corson compact spaces that are not semi-Eberlein. 

Joint work with Antonio Aviles.