BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Ludovic Patey (Institut Camille Jordan\, Lyon) DTSTART:20210211T190000Z DTEND:20210211T200000Z DTSTAMP:20260423T021154Z UID:OLS/43 DESCRIPTION:Title: Can onical notions of forcing in computability theory\nby Ludovic Patey (I nstitut Camille Jordan\, Lyon) as part of Online logic seminar\n\n\nAbstra ct\nIn reverse mathematics\, a proof that a problem P does not imply a pro blem Q is usually done by constructing a computable instance of Q whose so lutions are computationally complex\, while proving that every simple inst ance of P has a simple solution\, using a notion of forcing. In its full g enerality\, the notion of forcing could depend on both P and Q\, but in mo st cases\, the notion of forcing for building solutions to P does not depe nd on Q. This suggests the existence of a "canonical" notion of forcing fo r P\, that is\, a notion of forcing such that all the relevant separation proofs can be obtained without loss of generality with sufficiently generi c sets for this notion. We settle a formal framework for discussing this q uestion\, and give preliminary results. This is a joint work with Denis Hi rschfeldt.\n LOCATION:https://researchseminars.org/talk/OLS/43/ END:VEVENT END:VCALENDAR