BIMSA-YMSC Geometry and Dynamics Seminar


Description

Seminar covering a broad range of topics in geometry and/or dynamics.

Date and Time: Wednesdays at 1:30-2:30pm (Beijing time)

Zoom Meeting ID: 815 762 8413 (Passcode: BIMSA)


Upcoming Talk

April 16 at 1:30pm (Beijing time)

Yinbang Lin (Tongji University)

Title: An update on the Riemann-Roch and Brill-Noether problems over surfaces

Abstract: We try to bound the dimension of the global sections of semistable sheaves in terms of the rank and the first Chern class. This improves the explicit Le Potier-Simpson bound when the first Chern class is small compared to the rank. In some cases, we also obtain the asymptotic bound as the second Chern class goes to infinity, using Bridgeland stability conditions. Understanding these bounds is the foundation of the Brill-Noether problem. Over K3 surfaces of Picard number one, we show examples of Brill-Noether loci which are non-empty and irreducible of expected dimensions. Besides their fundamental importance, we are also motivated by the Verlinde/Segre correspondence over surfaces. This is work in progress jointly with Thomas Goller and Zhixian Zhu.


Spring 2025 Schedule

March 5: Tomohiro Karube (The University of Tokyo), The noncommutative MMP for blowup surfaces

April 2: Ki Fung Chan (The Chinese University of Hong Kong), 3d Mirror Symmetry is 2d Mirror Symmetry

April 16: Yinbang Lin (Tongji University), An update on the Riemann-Roch and Brill-Noether problems over surfaces

May 14: Ziqi Liu (University of Milan) [Special time: 2:10-3:10pm]

May 28: Chao-Ming Lin (Ohio State University)

June 4: Ziyu Zhang (ShanghaiTech University)


Fall 2024 Schedule

September 25: Shizhuo Zhang (IBS-CGP), 1-nodal prime Fano threefolds parametrized by Bridgeland stable objects in Kuznetsov component of del Pezzo threefolds [slides]

October 23: Kohei Kikuta (Osaka University/University of Edinburgh), Geometrical finiteness for automorphism groups via cone conjecture [slides]

October 30: Omar Kidwai (The Chinese University of Hong Kong), Quadratic differentials and Donaldson-Thomas invariants

November 6: Vanja Zuliani (Université Paris-Saclay), Semiorthogonal decompositions from quantum cohomology

November 20: Aimeric Malter (BIMSA), Toric Exoflops

November 27: Nantao Zhang (Tsinghua University), Global dimension of geometric stability condition [slides]

December 4: Benjamin Sung (UCSB), The Stability Manifold of ExExE


Spring 2024 Schedule

March 13: Guillaume Tahar (Beijing Institute of Mathematical Sciences and Applications), Isoresidual fibration and resonance arrangements [slides]

March 20: Yat-Hin Suen (Korea Institute for Advanced Study), Toric vector bundles, non-abelianisation, and spectral networks [slides]

March 27: Ziming Nikolas Ma (Southern University of Science and Technology), Deformation theory, Fukaya's conjecture and the Gross-Siebert program [slides]

April 10: Jun Zhang (University of Science and Technology of China), Metric geometry on Grothendieck groups in symplectic geometry [slides]

April 17: Takumi Otani (Tsinghua University), The number of full exceptional collections for orbifold projective lines [slides]

May 8: Hiroki Matsui (Tokushima University), The spectrum of a triangulated category and its applications to algebraic geometry [slides]

May 15: Asilata Bapat (Australian National University), Categorical q-deformed rational numbers via Bridgeland stability conditions [slides]

May 22: Xun Yu (Tianjin University), Automorphism groups of smooth hypersurfaces

May 29: Fei Yu (Zhejiang University), Hassett-Keel program and moduli spaces of Abelian differentials [slides]


Fall 2023 Schedule

December 6: Jia Jia (Tsinghua University), Wild automorphisms of compact complex spaces [slides]

December 13: Atsushi Kanazawa (Keio University), Mirror symmetry and rigid structures of generalized K3 surfaces [slides]

December 20: Sangjin Lee (Korea Institute for Advanced Study), A lower-bound of entropy from symplectic topology [slides]

January 3: Pranav Pandit (International Centre for Theoretical Sciences), Formal deformations of higher categories

January 10: Dongjian Wu (Tsinghua University), Riemann-Hilbert problems from rank 3 WKB spectral networks