BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Carolina Araujo (IMPA) DTSTART:20201202T183000Z DTEND:20201202T200000Z DTSTAMP:20260423T004141Z UID:BRAG/35 DESCRIPTION:Title: Bi rational geometry of Calabi-Yau pairs and 3-dimensional Cremona transforma tions\nby Carolina Araujo (IMPA) as part of Brazilian algebraic geomet ry seminar\n\n\nAbstract\nRecently\, Oguiso addressed the following questi on\, attributed to Gizatullin: ``Which automorphisms of a smooth quartic K 3 surface $D\\subset \\PP^3$ are induced by Cremona transformations of the ambient space $\\mathbb{P}^3$?'' \n\nWhen $D\\subset \\mathbb{P}^3$ is a smooth quartic surface\, $(\\mathbb{P}^3\,D)$ is an example of a Calabi-Y au pair\, that is\, a pair $(X\,D)$\, consisting of a normal projective va riety $X$ and an effective Weil divisor $D$ on $X$ such that $K_X+D\\sim 0 $. Gizatullin's question is about birational properties of the Calabi-Yau pair $(\\mathbb{P}^3\,D)$. In this talk\, I will explain a general framewo rk to study the birational geometry of mildly singular Calabi-Yau pairs. T hen I will focus on the case of singular quartic surfaces $D\\subset \\mat hbb{P}^3$. Our results illustrate how the appearance of increasingly worse singularities in $D$ enriches the birational geometry of the pair $(\\mat hbb{P}^3\, D)$\, and lead to interesting subgroups of the Cremona group of $\\mathbb{P}^3$.\n\nThis is joint work with Alessio Corti and Alex Massar enti.\n LOCATION:https://researchseminars.org/talk/BRAG/35/ END:VEVENT END:VCALENDAR