Friday, September 13, 2013 - 11:00 to 12:00
703 Thackeray Hall
Abstract or Additional Information
A partially ordered set P is said to have calibre (ω1,ω) if every uncountable subset of P contains an infinite subset with an upper bound in P. It is conjectured that if X is a compact space such that K(X2/D) has calibre (ω1,ω), where D is the diagonal in X2 and K(Y) denotes the hyperspace of compact subsets of Y, then X is metrizable. In this talk, we show that the weaker condition that a compactum X has relative calibre (ω1,ω) in K(X2/D) does not imply metrizability of X. The example exploits a technique of van Douwen.