题目：Tukey Order, Small Cardinals, and Off-diagonal metrization

报告人:  冯自勤教授

 (Auburn University)

Abstract : In 1945, Sneider proved that any compact space X with a G_/delta-diagonal is metrizable. Movited by this result, we define a space with an M-diagonal. We investigate spaces with a Q-diagonal, where Q is the space of rational numbers, and prove that any compact space with a Q-diagonal is metrizable. This answers an open question raised by Cascales, Orihuela, and Tkachuk positively. In the proof, we use Tukey order and a few independent statements of small cardinals.

时间：6月14日（周五）下午15:00-16:00

地点：565net必赢客户端本部教二楼 727 教室

联系人：牟磊

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