BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Nuno Cardoso / Aline Zanardini (University of Miami / University o f Pennsylvania) DTSTART:20200826T183000Z DTEND:20200826T200000Z DTSTAMP:20260423T021604Z UID:BRAG/20 DESCRIPTION:Title: To wards a new technique to compute Orlov spectra / Stability of Halphen penc ils of index two\nby Nuno Cardoso / Aline Zanardini (University of Mia mi / University of Pennsylvania) as part of Brazilian algebraic geometry s eminar\n\n\nAbstract\nTowards a new technique to compute Orlov spectra\, b y Nuno Cardoso \n\nAbstract: A generator of a triangulated category is an object from which we can obtain the whole category through certain operati ons. Associated to a generator\, there is the notion of the generation tim e\, which is the number describing how long the rebuilding process takes. The generation time of the fastest generator is called the Rouquier dimens ion of the category and it is conjectured that the Rouquier dimension of t he derived category of a smooth projective variety of dimension n is exact ly n. Orlov suggested that in order to extract additional geometric inform ation from the category\, one should study all possible generation times – the Orlov spectrum. Later\, Ballard\, Favero and Katzarkov developed c onsiderably our understanding of the topic\, making connections to rationa lity\, computing the Orlov spectrum in several cases and finding bounds fo r it. In this talk\, we will review part of their results and discuss our work in progress on a new technique to compute the Orlov spectrum\, which takes inspiration on Abouzaid's criterion for generating the Fukaya catego ry in terms of open-closed maps.\n\n--xx--xx--\n\nStability of Halphen pen cils of index two\, by Aline Zanardini\n\nAbstract: In this talk I will pr esent some results about the stability\, in the sense of geometric invaria nt theory\, of Halphen pencils of index two under the action of SL(3). The se are pencils of plane curves of degree six having nine (possibly infinit ely near) base points of multiplicity two. Inspired by the work of Miranda on pencils of plane cubics\, I will explain how to explore the geometry o f the associated rational elliptic surfaces. I will also show that the lo g canonical threshold plays an important role. This work is part of my PhD thesis at the University of Pennsylvania under the supervision of Antonel la Grassi.\n LOCATION:https://researchseminars.org/talk/BRAG/20/ END:VEVENT END:VCALENDAR