On universality of countable powers of absolute retracts

• Дата: 1996
• Автори: Banakh, T. O., Radyl, Т., Банах, Т. О., Раділ, Т.
• Формат: Стаття
• Мова: Англійська
• Опубліковано: Institute of Mathematics, NAS of Ukraine 1996
• Онлайн доступ: https://umj.imath.kiev.ua/index.php/umj/article/view/5317
• Назва журналу: Ukrains’kyi Matematychnyi Zhurnal

We construct an absolute retract X of arbitrarily high Borel complexity such that the countable power X ω is not universal for the Borelian class A 1 of sigma-compact spaces, and the product X ω x ∑, where ∑ is the radial interior of the Hilbert cube, is not universal for the Borelian class A 2 of a...