Lundi 5 mai 2014
IRMA
The "Joint Seminar in Algebraic and Complex Geometry" is a research seminar, organized by the research groups in Basel, Freiburg, Nancy and Strasbourg. The seminar meets roughly twice per semester in Strasbourg, for a full day. There are about four talks per meeting, both by invited guests and by speakers from the organizing universities. We aim to leave ample room for discussions and for a friendly chat.
The talks are open for everyone. Contact one of the organizers if you are interested in attending the meeting. We have some (very limited) funds that might help to support travel for some junior participants.
The seminar will meet in Strasbourg, May 5th in the conference room of the institute.
Organizer in Strasbourg : G. Pacienza
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Lundi 5 mai 2014
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10:30
Olivier Benoist, IRMA
Complete families of smooth space curves
Abstract: In this talk, we will study complete families of smooth space curves, that is complete subvarieties of the Hilbert scheme of smooth curves in . On the one hand, we will construct non-trivial examples of such families. On the other hand, we obtain necessary conditions for a complete family of smooth polarized curves to induce a complete family of non-degenerate smooth space curves. Both results rely on the study of the strong semistability of certain vector bundles. -
11:45
Tomasz Szemberg, Krakow and Freiburg
The effect of points fattening
Abstract: I recall briefly results due to Bocci and Chiantini on the effect of points fattening on the projective plane. Then I will report on some generalizations to other surfaces. The core of the lecture will be devoted to higher dimensional analogies. Results in that part were obtained jointly with Thomas Bauer (Marburg). -
14:30
Chenyang Xu, Beijing
Maximal pole of motivic Zeta function
Abstract: We prove a conjecture of Veys, which says that the opposite of the log canonical threshold is the only possible pole of maximal order of the motivic zeta function over a field of characteristic zero. If time permits, we will also discuss how to apply our method to study a family of Calabi-Yau varieties and prove properties for the weight function associated with a degeneration.(joint with Johannes Nicaise) -
16:00
Gianluca Pacienza, IRMA
Families of rational curves on holomorphic symplectic varieties
Abstract: I will report on a joint work with François Charles, in which we study families of rational curves on certain irreducible holomorphic symplectic varieties. In particular, we prove that projective holomorphic symplectic fourfolds of (K3)^[2]-type contain uniruled divisors and rationally connected lagrangian surfaces. I will also mention some applications to the study of Chow groups of such varieties, generalizing analogous results due to Beauville and Voisin on K3 surfaces.