BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Catherine Hsu (Swarthmore College) DTSTART:20230216T233000Z DTEND:20230217T003000Z DTSTAMP:20260422T054353Z UID:SFUQNTAG/81 DESCRIPTION:Title: Explicit non-Gorenstein R=T via rank bounds\nby Catherine Hsu (Swart hmore College) as part of SFU NT-AG seminar\n\nLecture held in K-9509.\n\n Abstract\nIn his seminal work on modular curves and the Eisenstein ideal\, Mazur studied the existence of congruences between certain Eisenstein ser ies and newforms\, proving that Eisenstein ideals associated to weight 2 c usp forms of prime level are locally principal. In this talk\, we'll explo re generalizations of Mazur's result to squarefree level\, focusing on rec ent work\, joint with P. Wake and C. Wang-Erickson\, about a non-optimal l evel N that is the product of two distinct primes and where the Galois def ormation ring is not expected to be Gorenstein. First\, we will outline a Galois-theoretic criterion for the deformation ring to be as small as poss ible\, and when this criterion is satisfied\, deduce an R=T theorem. Then we'll discuss some of the techniques required to computationally verify th e criterion.\n LOCATION:https://researchseminars.org/talk/SFUQNTAG/81/ END:VEVENT END:VCALENDAR