On April 26, 2024, the next meeting of the Belgian-Dutch Algebraic Geometry seminar will be held at Utrecht University. Location: Ruppert Rood (Utrecht Science Park).
Programme (click a title to show/hide the abstract) |
||
13:15-14:15 | Soumya Sankar (Utrecht) | On the rationality of conic bundle threefolds
Abstract: One of the major programs in algebraic geometry seeks to understand when a given variety is rational, and what the obstructions to rationality are. From this perspective, conic bundles are a geometrically rich class of varieties. Hassett—Tschinkel and Benoist—Wittenberg recently introduced a rationality obstruction that can be translated into a question about curve classes on threefolds. I will talk about joint work with Sarah Frei, Lena Ji, Bianca Viray and Isabel Vogt, where we study curve classes on certain conic bundle threefolds over arbitrary fields of odd characteristic. We then use the description of these classes to study the rationality of such varieties
|
14:45-15:45 | Dimitri Wyss (EPFL) | Non-archimedean integration on quotients
Abstract: Motivated by mirror symmetry, Batyrev defines 'stringy' Hodge numbers for a variety X with Gorenstein canonical singularities using motivic integration. While in general it is an open question, whether these numbers are related to a cohomology theory, the orbifold formula shows, that if X has quotient singularities, they agree with Chen-Ruan's orbifold Hodge numbers.
I will explain how to generalize this orbifold formula to quotients of smooth varieties by linear algebraic groups. As an application we obtain identifications of stringy Hodge numbers with enumerative invariants, so-called BPS-invariants, in the case when X is the moduli space of a CY1 category. This is joint work with Michael Groechenig and Paul Ziegler.
|
16:15-17:15 | Jef Laga (Cambridge) | Ceresa cycles of bielliptic Picard curves
Abstract: The Ceresa cycle is a canonical algebraic 1-cycle in the Jacobian of a curve with a marked point. In some sense it is the simplest non-trivial canonical algebraic cycle 'beyond homology' and as such it is a natural testing ground for our knowledge of cycles on abelian varieties. The Ceresa cycle vanishes for all hyperelliptic curves, but beyond this little is known about the locus of curves in Mg where this cycle is torsion. In this talk I will discuss joint work with Ari Shnidman where we find this torsion locus for a special family of genus-3 curves called bielliptic Picard curves, and hint at some further directions.
|
October 27, 2023, at Leiden University |
||
Rahul Pandharipande (ETH Zürich) | Abelian varieties, curves, and the Hilbert scheme of points of the planec | |
Farbod Shokrieh (Univ. of Washington) | Arakelov invariants and non-archimedean geometry | |
Yajnaseni Dutta (Leiden University) | Birational self-maps on Hyperkähler (HK) manifolds | |
March 24, 2023, at Radboud University Nijmegen |
||
Alexander Petrov (Harvard and MPI Bonn) | Decomposability of the de Rham complex in positive characteristic | |
Sabrina Pauli (Duisburg-Essen)) | Counting curves over an arbitrary field using tropical geometry | |
Emanuele Macrì (Orsay) | Hyper-Kähler manifolds and Lagrangian fibrations | |
December 9, 2022, at the University of Amsterdam |
||
Piotr Achinger (IMPAN) | The Riemann-Hilbert correspondence for rigid spaces | |
Laura Pertusi (Milan) | Moduli spaces of stable objects in Enriques categories | |
Dustin Clausen (Copenhagen) | Algebraic geometry from the solid perspective | |
September 30, 2022, at the KU Leuven |
||
Javier de Bobadilla (BCAM) | Monodromy at radius zero and equimultiplicity of families with constant Milnor number | |
Valentijn Karemaker (Utrecht) | The Gauss problem for central leaves | |
Gebhard Martin (Bonn) | On the non-degeneracy of Enriques surfaces | |
November 8, 2019, at the University of Antwerp |
||
Lie Fu (Lyon and Nijmegen) | Orbifold products on motivic cohomology and hyper-Kaehler resolution conjectures | |
Špela Špenko (UL Bruxelles) | Perverse schobers in geometric invariant theory | |
Stefan Kebekus (Freiburg) | Extension Theorems for differential forms and applications | |
June 21, 2019, at the University of Amsterdam |
||
Diletta Martinelli (Edinburgh) | On the geometry of contractions of the Moduli Space of sheaves of a K3 surface | |
Zsolt Patakfalvi (EPFL) | On the Beauville-Bogomolov decomposition in positive characteristic | |
Yichao Tian (Strasbourg) | Geometry of unitary Shimura varieties at non-quasi-split primes and arithmetic applications | |
February 1, 2019, at Utrecht University |
||
Dan Petersen (Stockholm University) | Tautological classes with twisted coefficients | |
Donatella Iacono (Università di Bari) | DG-Lie algebras and deformation of pairs | |
Georg Oberdieck (University of Bonn) | Quantum cohomology of the Hilbert scheme of pairs | |
September 20 and 21, 2018 at Radboud University Nijmegen |
Ching-Li Chai (UPenn) | Sustained p-divisible groups and the foliation on moduli spaces of abelian varieties |
Jörg Wildeshaus (Paris 13) | Weights and conservativity | |
Kestutis Cesnavicius (CNRS/Paris-Sud) | Purity for the Brauer group | |
Claire Voisin (Collège de France) | Gonality and zero-cycles of abelian varieties | |
Victoria Hoskins (FU Berlin) | On the motive of the stack of vector bundles on a curve | |
Richard Thomas (Imperial College) | Refined Vafa-Witten invariants for projective surfaces | |
Piotr Achinger (IMPAN, Warsaw) | Serre-Tate theory for Calabi-Yau varieties | |
June 8, 2018 at the KU Leuven |
||
Arend Bayer (Edinburgh) | Families of Hyperkaehler varieties via families of stability conditions | |
Christian Liedtke (Technische Universität München) | A Néron-Ogg-Shafarevich criterion for K3 Surfaces | |
José Burgos Gil (ICMAT, Madrid) | Grothendieck's period conjecture and zeta values | |
March 23, 2018 at Leiden University |
||
Videos of the lectures are available via youtube. | ||
Florian Ivorra (FRIAS, Freiburg) | Quasi-unipotent motives | |
Peter Jossen (ETH Zürich) | Galois groups and Motivic Fundamental groups | |
Lionel Darondeau (KU Leuven) | Jet differentials and hyperbolicity | |
December 15, 2017 at Radboud University Nijmegen |
||
Johannes Nicaise (Imperial College and Leuven) | Specialization of (stable) rationality in families with mild singularities | |
Javier Fresán (École Polytechnique) | Exponential motives | |
Michael Groechenig (FU Berlin) | p-adic integration for the Hitchin system | |
December 9, 2016 at the University of Amsterdam |
||
June Huh (Princeton) | Enumeration of points, lines, planes, etc. | |
Dieter Kotschick (München) and Stefan Schreieder (Bonn) | The Hodge ring of Kähler manifolds | |
Bhargav Bhatt (Ann Arbor) | Derived splinters in mixed characteristic | |
April 22, 2016 at KU Leuven |
||
Sho Tanimoto (Copenhagen) | Towards a refinement of Manin's conjecture | |
John Christian Ottem (Oslo) | Effective cones of cycles on blow-ups of projective space | |
Bruno Chiarellotto (Padova) | Monodromy action and special fiber for semistable schemes over a DVR | |
December 11, 2015 at Leiden University |
||
David Holmes (Leiden) | Models of degenerating jacobians | |
Clément Dupont (MPIM Bonn) | Motives of bi-arrangements | |
Misha Verbitsky (ULB, Bruxelles) | Transcendental Hodge algebra | |
June 11 and 12, 2015 in Nijmegen, joint with NoGAGS |
||
Daniel Greb (Duisburg-Essen) | Movable curves and semistable sheaves | |
Klaus Künnemann (Regensburg) | A tropical approach to non-archimedean Arakelov geometry | |
Kevin Buzzard (Imperial College) | Pre-adic spaces and adic spaces | |
Tim Dokchitser (Bristol) | Local arithmetic of hyperelliptic curves | |
David Rydh (KTH Stockholm) | The local structure of Artin stacks | |
Lars Kindler (FU Berlin) | Ramification theory for D-modules in positive characteristic | |
Christian Lehn (Hannover) | Rational curves on singular cubic fourfolds | |
Ulf Kühn (Hamburg) | A geometric approach to constructing elements of K2 of curves | |
November 14, 2014 at the University of Amsterdam |
||
Minhyong Kim (Oxford) | Non-abelian reciprocity laws and Diophantine geometry | |
Mingmin Shen (UvA) | Multiplicative Chow-Künneth decompositions | |
Jakob Stix (Frankfurt) | Gorenstein orders and abelian varieties over finite fields | |
May 16, 2014 in Leuven |
||
Olivier Benoist (Strasbourg) | Complete families of smooth space curves | |
Frank-Olaf Schreyer (Saarbrücken) | Matrix factorizations and families of curves of genus 15 | |
Carel Faber (Utrecht) | On the cohomology of the moduli spaces of pointed curves of genus three | |
November 22, 2013 in Nijmegen |
||
Nero Budur (Leuven) | Cohomology jump loci | |
Stefan Schröer (Düsseldorf) | Wild quotient surface singularities | |
René Schoof (Rome) | Finite group schemes and abelian varieties with good reduction outside one prime | |
June 14, 2013 in Leiden |
||
Walter Gubler (Regensburg) | Normal toric varieties over valuation rings of rank 1 | |
Gaël Rémond (Bordeaux) | Isogenies and polarizations | |
Jean-Benoît Bost (Orsay) | Pluripotential theory, heights, and algebraization on arithmetic threefolds | |
José Ignacio Burgos Gil (ICMAT Madrid) | The singularities of the invariant metric of the sheaf of Jacobi forms on the universal elliptic curve | |
April 19, 2013 in Leuven |
||
Alejandro Soto (Regensburg) | Toric Varieties over a Valuation Ring | |
Sébastien Boucksom (Jussieu) | A uniform version of Izumi's theorem | |
Ariyan Javanpeykar (Leiden) | Bounds for Arakelov invariants - algorithmic and Diophantine applications | |
December 7, 2012 at the UvA |
||
Andrei Caldararu (Wisconsin) | Derived intersections | |
Eduard Looijenga (Utrecht) | Cohomological dimension of moduli spaces of curves | |
Daniel Huybrechts (Bonn) | Cycles on K3 surfaces | |
June 15, 2012 in Leuven |
||
Ted Chinburg (UPenn) | Small generators for S-arithmetic groups | |
Matthieu Romagny (Jussieu) | Models of groups schemes of roots of unity | |
Mircea Mustaţă (Michigan) | Adjoint line bundles in positive characteristic |