京都大学数理解析研究所の佐藤です。
6月25日11:00から、情報通信研究機構・脳情報通信融合研究センターの Matthew de Brecht氏に以下の講演をしていただくことになりましたので、 ご連絡いたします。どうぞお気軽にお越しください。 ========== Time: 11:00-12:00, 25 Jun, 2015 Place: Rm 478, Research Building 2, Main Campus, Kyoto University 京都大学 本部構内 総合研究2号館 4階478号室 http://www.kyoto-u.ac.jp/en/access/yoshida/main.html (Building 34) http://www.kyoto-u.ac.jp/ja/access/campus/map6r_y.htm (34番の建物)
Speaker: Matthew de Brecht (NICT, CiNet)
Title: Towards a descriptive set theory for QCB spaces.
Abstract: QCB spaces (quotients of countably based spaces) are a convenient cartesian closed category of topological spaces with important applications in computable analysis and for modeling the semantics of programming languages. However, they generally fail to be countably based and have very complicated topologies, which so far has been a major obstacle for obtaining a deep understanding of these spaces. In this talk, I will present recent joint work with M. Schroeder and V. Selivanov concerning a classification of QCB0 spaces according to the descriptive complexity of defining a basis for their topologies. Our approach provides useful tools for analyzing when one QCB space can be embedded into another, and has deep connections with the projective hierarchy from descriptive set theory. We will present some applications concerning the existence of universal QCB-spaces, as well as some results on the Kleene-Kreisel continuous functionals.