Past seminars: 2019-20

Categorification of 2d cohomological Hall algebras

Tuesday 17 September 2019

Speaker: Francesco Sala (IPMU Tokyo)
Location: J11
Time: 2.00pm

Partitions and Hilbert schemes of points

Tuesday 1 October 2019

Speaker: Paul Johnson (Sheffield)
Location: J11
Time: 12.00pm

Abstract: This will be a gentle, expository talk explaining some connections between the two objects in the title.

A Mayer-Vietoris theorem for Gromov-Witten theory

Tuesday 8 October 2019

Speaker: Dhruv Ranganathan (Cambridge)
Location: J11
Time: 12.00pm

The Stability Manifold of a Contraction Algebra

Tuesday 15 October 2019

Speaker: Jenny August (MPIM Bonn)
Location: J11
Time: 12.00pm

Quasimodular forms from Betti numbers

Thursday 17 October 2019

Speaker: Pierrick Bousseau (ETH)
Location: J11
Time: 3.00pm

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

Tuesday 22 October 2019

Speaker: Nick Sheridan (Edinburgh)
Location: J11
Time: 12.00pm

K-theoretic Donaldson-Thomas theory and the Hilbert scheme of points on a surface

Tuesday 29 October 2019

Speaker: Noah Arbesfeld (Imperial College London)
Location: J11
Time: 12.00pm

Abstract: Tautological bundles on Hilbert schemes of points often enter into enumerative and physical computations.

Strong positivity for quantum cluster algebras

Tuesday 5 November 2019

Speaker: Ben Davison (Edinburgh)
Location: J11
Time: 12.00pm

Abstract: I will discuss the positivity for quantum theta functions, a result of joint work with Travis Mandel.

Stability conditions on the derived category of coherent systems and Brill-Noether theory

Thursday 21 November 2019

Speaker: Soheyla Feyzbakhsh (Imperial College London)
Location: J11
Time: 12.00pm

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.

Non-archimedean and motivic integrals on the Hitchin fibration

Tuesday 3 December 2019

Speaker: Dimitri Wyss (École Polytechnique Fédérale de Lausanne)
Location: J11
Time: 12.00pm

Higher SL(k)-friezes

Tuesday 10 December 2019

Speaker: Sira Gratz (Glasgow)
Location: J11
Time: 12.00pm

Intersection theory of derived stacks

Wednesday 11 December 2019

Speaker: Adeel Khan (Regensburg)
Location: LT-B
Time: 3.00pm

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.

Generalisation of the Givental theory for the open WDVV equations

Wednesday 18 December 2019

Speaker: Alexandr Buryak (Leeds)
Location: J11
Time: 2.00pm

Abstract: The WDVV equations, also called the associativity equations, is a system of non-linear partial differential equations for one function that describes the local structure of a Frobenius manifold.

Smoothing toroidal crossing varieties

Tuesday 28 January 2020

Speaker: Helge Ruddat (Mainz)
Location: J11
Time: 12.00pm

Quantum modularity

Tuesday 18 February 2020

Speaker: William Mistegaard (IST Austria)
Location: F24
Time: 12.00pm

Cancelled - Etienne Mann (Angers)

Tuesday 17 March 2020

Speaker: Etienne Mann (Angers)
Location: F24
Time: 12.00pm

Tropical multiplicities from polyvector fields and QFT

Tuesday 21 April 2020

Speaker: Travis Mandel (Edinburgh)
Time: 3.30pm UK time
Online: ZOOM Meeting ID: 762 8025 8504, ask for password.