Logic-MLの皆さま、
今月26日開催の松山TGSAセミナーのお知らせを転送いたします。
藤田 博司（愛媛大学大学院理工学研究科）
-------- Forwarded Message -------- Subject: 松山 TGSA セミナーのお知らせ（１２月２６日） Date: Sat, 17 Dec 2016 18:29:24 +0000 From: Dmitri SHAKHMATOV [email protected] To: [email protected] CC: [email protected]
皆様、
「Matsuyama Seminar on Topology, Geometry, Set Theory and their Applications」（松山TGSAセミナー）のお知らせです。
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第27回のセミナー
日時: 2016年12月26日（月） 16:45〜17:45
場所: 愛媛大学理学部2号館2階，大演習室 (201号室)
講演者: Franklin D. Tall (University of Toronto, Canada)
題目: Definable versions of Menger's conjecture
概要： A topological space is Menger if, given a countable sequence of open covers, there is a finite selection from each of them, so that the union of the selections is a cover. The Menger property lies strictly between sigma-compactness and Lindelofness. In 1925 Hurewicz conjectured that Menger was equivalent to sigma-compact in metrizable spaces. This was refuted by Chaber and Pol in 2002. However, for spaces which are in some sense ``definable", the situation is less clear. Our principal result (joint with S. Todorcevic and S. Tokgoz) is that Hurewicz' Conjecture for projective sets of reals is equiconsistent with an inaccessible cardinal. In general topological spaces, the situation is more complicated, but we have a variety of similar results for co-analytic spaces, i.e. spaces having Cech-Stone remainders which are continuous images of the space of irrationals.
講演終了後に交流会を予定しています。交流会にご参加いただける方はシ ャクマトフ[email protected]までご一報お願い致します。
以上、よろしくお願い申し上げます。
世話人（五十音順） 井上友喜 尾國新一 シャクマトフ ディミトリ 野倉嗣紀 平出耕一 平田浩一 藤田博司 山内貴光
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