Birational Complexity of Algebraic Varieties: December 12-16, 2022

Participant List Schedule Bus Schedule from Pass Way

Organized by:

Ignacio Barros (Université Paris-Saclay)
Robert Lazarsfeld (Stony Brook University)
Olivier Martin (Stony Brook University) 
David Stapleton (University of Michigan) 
Susanna Zimmermann (Université d’Angers)

How complicated can an algebraic variety be? From the perspective of birational geometry the simplest varieties are rational or unirational. Determining whether or not a variety is rational is a famously hard problem of classical and modern interest. New techniques developed in the past decade have realized exciting progress in deciding rationality and in understanding the behavior of rationality.

Beyond the rationality problem itself there are many interesting questions one can ask concerning the birational complexity of an algebraic variety. Can one bound its irrationality? What sort of subvarieties cover it? How complicated is its birational automorphism group? What happens over different fields?

Cycle-theoretic techniques, motivic integration, measures of irrationality, degeneration, and derived categorical methods are some of the tools that have been developed to attack these questions in recent years. This workshop will bring together mathematicians involved with these different directions to share ideas and recent progress.

This event will be preceded by the RTG/SCGP Graduate Workshop on the Birational Complexity of Algebraic Varieties (December 5-9, 2022, SCGP). We encourage students to attend both events but apply to the graduate workshop only. That application will allow students to express interest in the research workshop as well.

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Talk Schedule

Time Title Speaker Location
9:00am Breakfast N/A SCGP Cafe
9:30am Finite subgroups of Cremona groups and representation dimension Alexander Duncan SCGP 102
10:30am Coffee Break N/A SCGP Cafe
11:00am Birational maps of Severi-Brauer surfaces, with applications to Cremona groups of higher rank Julia Schneider SCGP 102
12:00pm Lunch N/A SCGP Cafe
2:00pm Curves on K3 surfaces Frank Gounelas SCGP 102
3:00pm Tea Time N/A SCGP Cafe
3:30pm Rationality of real conic bundles with quartic discriminant curve Lena Ji SCGP 102

Time Title Speaker Location
9:00am Breakfast N/A SCGP Cafe
9:30am Curves on very general hypersurfaces Nathan Chen SCGP 102
10:30am Coffee Break N/A SCGP Cafe
11:00am Derived categories of varieties with rational singularities Evgeny Shinder SCGP 102
12:00pm Lunch N/A SCGP Cafe
2:00pm Some uniform bounds for Chow groups Alena Pirutka SCGP 102
3:00pm Tea Time N/A SCGP Cafe
3:30pm Non-algebraic geometrically trivial cohomology classes over finite fields Fumiaki Suzuki SCGP 102
4:45pm Speed Talks Various SCGP 102

Time Title Speaker Location
8:30am Breakfast N/A SCGP Cafe
9:00am Hodge classes on the moduli space of W(E6) covers and the geometry of A6 Elham Izadi SCGP 102/ZOOM
10:00am Coffee Break N/A SCGP Cafe
10:30am Restrictions on rational surfaces in general Fano hypersurfaces Roya Beheshti SCGP 102
11:30am Coffee Break N/A SCGP 102
12:00pm Actions of Cremona groups on CAT(0) cube complexes Christian Urech SCGP 102
1:00pm Lunch N/A SCGP Cafe
3:00pm Tea Time N/A SCGP Cafe

Time Title Speaker Location
9:00am Breakfast N/A SCGP Cafe
9:30am The diagonal of quartic fivefolds Stefan Schreieder SCGP 102
10:30am Coffee Break N/A SCGP Cafe
11:00am Bijective Cremona transformations of the plane Masahiro Nakahara SCGP 102
12:00pm Lunch N/A SCGP Cafe
2:00pm Estimates on the growth of irrationality for moduli spaces of K3 surfaces Kuan-Wen Lai SCGP 102
3:00pm Tea Time N/A SCGP Cafe
3:30pm Minimal degree fibrations and the asymptotic degree of irrationality of divisors David Stapleton SCGP 102
4:45pm Speed Talks Various SCGP 102
6:00pm Banquet N/A SCGP Cafe

Time Title Speaker Location
9:00am Breakfast N/A SCGP Cafe
9:30am Open problems on Cremona groups Susanna Zimmerman SCGP 102
10:30am Coffee Break N/A SCGP Cafe
11:00am Geometry of the Abel-Jacobi map and stable birational invariants Claire Voisin SCGP 102
12:00pm Lunch N/A SCGP Cafe
3:00pm Tea Time N/A SCGP Cafe