We run a weekly Algebraic Geometry and Mathematical Physics Seminar - details below.

On Wednesday at 2pm there is the **Pure maths Colloquium**, and on Monday at 3pm we organise a **learning seminar on K3 surfaces** (calendar, notes, Huybrechts's book).

Talks are usually in room J11.

In November 2019, 13th-14th, we host a two-days GLEN workshop.

For a complete list of seminars hosted at the School of Maths and Stats, look at This week’s seminars and This semester’s seminars.

Categorification of 2d cohomological Hall algebras

*Abstract:* Let M denote the moduli stack of either coherent sheaves on a smooth projective surface or Higgs sheaves on a smooth projective...
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Partitions and Hilbert schemes of points

*Abstract:* This will be a gentle, expository talk explaining some connections between the two objects in the title. I will begin with...
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A Mayer-Vietoris theorem for Gromov-Witten theory

*Abstract:* The Gromov-Witten theory of a smooth variety X is a collection of invariants, extracted from the topology of the space of ...
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The Stability Manifold of a Contraction Algebra

*Abstract:* For a finite dimensional algebra, Bridgeland stability conditions can be viewed as a continuous generalisation of tilting theory, providing...
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Quasimodular forms from Betti numbers

*Abstract:* I will explain how to construct quasimodular forms starting from Betti numbers of moduli spaces of dimension 1 coherent sheaves on P2. This gives a proof of some stringy predictions about the refined topological string theory of local P2 in the Nekrasov-Shatashvili limit. Partly based on work in progress with Honglu Fan, Shuai Guo, and Longting Wu.

The Gamma and SYZ conjectures: a tropical approach to periods

*Abstract:* I'll start by explaining a new method of computing asymptotics of period integrals using tropical geometry, via some...
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K-theoretic Donaldson-Thomas theory and the Hilbert scheme of points on a surface

*Abstract:* Tautological bundles on Hilbert schemes of points often enter into enumerative and physical computations. I'll explain how to use the Donaldson-Thomas theory of ...
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Strong positivity for quantum cluster algebras

*Abstract:* I will discuss the positivity for quantum theta functions, a result of joint work with Travis Mandel. For...
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Stability conditions on the derived category of coherent systems and Brill-Noether theory

*Abstract:* A classical method to study Brill-Noether locus of higher rank semistable vector bundles on curves is to examine the stability of coherent systems. To have an abelian category we enlarge the...
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Non-archimedean and motivic integrals on the Hitchin fibration

*Abstract:* Based on mirror symmetry considerations, Hausel and Thaddeus conjectured an equality between ‘stringy’ Hodge numbers for...
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Higher SL(k)-friezes

*Abstract:* Classical frieze patterns are combinatorial structures which relate back to Gauss’ Pentagramma Mirificum, and have been extensively studied by Conway and Coxeter in the 1970’s....
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Intersection theory of derived stacks

*Abstract:* I will discuss how various formalisms of intersection theory (Chow groups, K-theory, cobordism) can be extended to the setting of derived schemes and stacks. This gives a new approach to virtual phenomena such as the virtual fundamental class and virtual Riemann-Roch formulas.

GLEN meetings at Sheffield: 2018, 2016

Learning seminars:

- 2018/19: Toric Varieties
- 2017/18: Stacks; and Singularity Category of ADE Singularities
- 2016/17: Topics in Derived Categories; and Singularity Category, MCM modules and Matrix Factorization