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SUMMARY:Duarte Maia Nascimento (University of Chicago)
DTSTART:20260917T180000Z
DTEND:20260917T190000Z
DTSTAMP:20261004T233927Z
UID:OLS/217
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/OLS/217/">Es
 caping Tennenbaum's Theorem</a>\nby Duarte Maia Nascimento (University of 
 Chicago) as part of Online logic seminar\n\n\nAbstract\nTennenbaum's theor
 em states that PA does not admit any\ncomputable model other than the "usu
 al natural numbers" (this is called\nthe standard model). In 2022\, Fedor 
 Pakhomov proved that this theorem is\nfragile in regards to how PA is expr
 essed\, by constructing a theory that\nis definitionally equivalent to PA 
 (roughly: "it's PA but with a\ndifferent choice of symbols") for which the
 re is a computable\nnonstandard model. I will introduce the audience to th
 is result and\,\ntime allowing\, present the way in which we have been abl
 e to improve on\nPakhomov's original construction and some remaining open 
 questions.\n
LOCATION:https://researchseminars.org/talk/OLS/217/
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