BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Nora Szakacs (University of York) DTSTART:20200520T103000Z DTEND:20200520T113000Z DTSTAMP:20260423T011055Z UID:YSseminar/3 DESCRIPTION:Title: Simplicity of contracted inverse semigroup algebras\nby Nora Szakacs (University of York) as part of York semigroup seminar\n\n\nAbstract\nIf $S$ is an inverse semigroup with a zero element\, the contracted semigroup algebra $K_0S$ is obtained from the semigroup algebra by identifying the zero of $S$ with the zero of the field. In the talk\, we examine when $K_0 S$ is simple. It is easy to see that $S$ congruence-free is a necessary co ndition\, as non-trivial congruences of $S$ give rise to non-trivial ideal s of $K_0S$. It has been known for long that this condition is not suffici ent however. Munn in the late 70's asked to characterize when a congruence -free inverse semigroup with zero has a simple contracted semigroup algebr a. A partial answer was given by Steinberg in 2016\, under the additional assumption that the inverse semigroup is Hausdorff. In the talk\, we prese nt a complete answer to Munn's question.\n LOCATION:https://researchseminars.org/talk/YSseminar/3/ END:VEVENT END:VCALENDAR