BEGIN:VCALENDAR VERSION:2.0 PRODID:ILLC Website X-WR-TIMEZONE:Europe/Amsterdam BEGIN:VTIMEZONE TZID:Europe/Amsterdam X-LIC-LOCATION:Europe/Amsterdam BEGIN:DAYLIGHT TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST DTSTART:19700329T020000 RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:+0200 TZOFFSETTO:+0100 TZNAME:CET DTSTART:19701025T030000 RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU END:STANDARD END:VTIMEZONE BEGIN:VEVENT UID:/NewsandEvents/Archives/2015/newsitem/6874/22- May-2015-Cool-Logic-Hugo-Nobrega DTSTAMP:20150518T000000 SUMMARY:Cool Logic, Hugo Nobrega ATTENDEE;ROLE=Speaker:Hugo Nobrega DTSTART;TZID=Europe/Amsterdam:20150522T180000 DTEND;TZID=Europe/Amsterdam:20150522T190000 LOCATION:ILLC Seminar Room (F1.15), Science Park 1 07, Amsterdam DESCRIPTION:Descriptive set theory (DST) is the st udy of the definable sets of real numbers and simi lar topological spaces. One of DST's main driving questions is: What can we say about a set if all t hat we know is that it is definable with a certain complexity? For example, we know that if a set is the projection of a closed subset of the real pla ne then it cannot be a counterexample to the Conti nuum Hypothesis. On the other hand, the usual axio ms of set theory don't determine whether the same can be said of all *complements* of such sets! On e especially interesting space studied in DST is t he Baire space, composed of the infinite sequences of natural numbers. The topology of this space ha s a certain computational-combinatorial flavor whi ch makes many arguments more intuitive than in oth er spaces. Another nice aspect of this space is th at it lends itself quite naturally to analysis by infinite games, which I hope to convince you of in this talk. I will start with a brief descriptio n of some games which have far-reaching consequenc es for set theory and the foundation of mathematic s. The main focus of the talk will be the games wh ich characterize interesting classes of functions in Baire space, where I will describe results by W adge, Duparc, Andretta, Semmes, and (time permitti ng) yours truly. I will assume no prior knowledge other than some basic mathematics, such as the def inition of a topology. For more information, see https://www.illc.uva.nl/coollogic/ or contact cool logic.uva at gmail.com X-ALT-DESC;FMTTYPE=text/html:\n

Descript ive set theory (DST) is the study of the definable sets of real numbers and similar topological spac es. One of DST's main driving questions is: What c an we say about a set if all that we know is that it is definable with a certain complexity? For exa mple, we know that if a set is the projection of a closed subset of the real plane then it cannot be a counterexample to the Continuum Hypothesis. On the other hand, the usual axioms of set theory don 't determine whether the same can be said of all * complements* of such sets!
\n One espec ially interesting space studied in DST is the Bair e space, composed of the infinite sequences of nat ural numbers. The topology of this space has a cer tain computational-combinatorial flavor which make s many arguments more intuitive than in other spac es. Another nice aspect of this space is that it l ends itself quite naturally to analysis by infinit e games, which I hope to convince you of in this t alk.
\n I will start with a brief desc ription of some games which have far-reaching cons equences for set theory and the foundation of math ematics. The main focus of the talk will be the ga mes which characterize interesting classes of func tions in Baire space, where I will describe result s by Wadge, Duparc, Andretta, Semmes, and (time pe rmitting) yours truly. I will assume no prior know ledge other than some basic mathematics, such as t he definition of a topology.

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For more information, see https://www. illc.uva.nl/coollogic/ or contact coollogic.uva at gmai l.com

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