BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Claude Laflamme (University of Calgary) DTSTART:20230504T200000Z DTEND:20230504T210000Z DTSTAMP:20260422T214834Z UID:ReginaGupta/1 DESCRIPTION:Title: How many siblings do you have? ... with a good lesson in mathematical writing!\nby Claude Laflamme (University of Calgary) as part of Univer sity of Regina H.N. Gupta memorial lecture\n\n\nAbstract\nTwo structures a re called siblings\, or equimorphic\, if each embeds in the other.\n\nSibl ings need not be isomorphic and the main mathematical objective is to desc ribe these equimorphic structures. A first step is simply the ability to c ount them (up to isomorphy)\, the so-called sibling number.\n\nSome early 2000 conjectures stated that the sibling number jumped to infinity as soon a single non-isomorphic sibling was found\, and we will review various de velopments in those directions over the years.\n\nOn the hand by chance an d to our surprise\, we learned that a 2008 thesis claimed a counterexample to one of those conjectures. We will argue that mathematical writing was the root cause of this claim not being verified until now\, and how it eve ntually triggered powerful counterexamples for several conjectures.\n LOCATION:https://researchseminars.org/talk/ReginaGupta/1/ END:VEVENT END:VCALENDAR