BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Shiva Chidambaram (University of Wisconsin\, Madison) DTSTART:20260323T200000Z DTEND:20260323T210000Z DTSTAMP:20260423T040043Z UID:NTBU/45 DESCRIPTION:Title: Ab elian threefolds with imaginary multiplication\, and elliptic curves attac hed to them\nby Shiva Chidambaram (University of Wisconsin\, Madison) as part of Boston University Number Theory Seminar\n\nLecture held in CDS Room 548 in Boston University.\n\nAbstract\nIt is an interesting problem t o construct algebraic curves whose Jacobians have extra endomorphisms. Whe n genus is 3\, there are two natural families of Jacobians with imaginary multiplication by $\\mathbb{Z}[i]$ and $\\mathbb{Z}[\\zeta_3]$\, coming fr om curves with a $\\mu_4$ or $\\mu_6$ action. We will report on new hypere lliptic families with imaginary multiplication by $\\mathbb{Z}[\\sqrt{-d}] $ for $d=2\,3\,4$\, and some instances of extending to any odd genus g. Ga lois representations allow one to naturally attach a CM elliptic curve to any abelian threefold with imaginary multiplication of signature (2\,1). F or the new families\, we will explicitly compute the attached CM elliptic curve. An analogue of this association was used by Laga-Shnidman to get re sults on vanishing of Ceresa cycles for Picard curves. Based on ongoing wo rk with Francesc Fite and Pip Goodman.\n LOCATION:https://researchseminars.org/talk/NTBU/45/ END:VEVENT END:VCALENDAR