Seminar/Colloquium Archive

MS Seminar (Mathematics - String Theory)

Speaker:	Laura Schaposnik (Univ. of Illinois Chicago)
Title:	TBA
Date:	Thu, Jun 25, 2026, 13:30 - 15:00
Place:	Seminar Room B

MS Seminar (Mathematics - String Theory)

Speaker:	David Klompenhouwer (University of Padova)
Title:	TBA
Date:	Tue, Apr 28, 2026, 13:30 - 15:00
Place:	Seminar Room A

MS Seminar (Mathematics - String Theory)

Speaker:	Xiaohan Yan (Toulouse Mathematics Institute)
Title:	TBA
Date:	Tue, Apr 21, 2026, 13:30 - 15:00
Place:	Seminar Room A

MS Seminar (Mathematics - String Theory)

Speaker:	Dam Son (University of Chicago)
Title:	TBA
Date:	Mon, Apr 13, 2026, 13:30 - 15:00
Place:	Seminar Room A

MS Seminar (Mathematics - String Theory)

Speaker:	Ben Davison (University of Edinburgh)
Title:	BPS cohomology of (0)-shifted symplectic stacks (4th talk in the four-lecture series)
Date:	Thu, Apr 02, 2026, 13:30 - 15:00
Place:	Seminar Room B

MS Seminar (Mathematics - String Theory)

Speaker:	Ben Davison (University of Edinburgh)
Title:	BPS cohomology of (0)-shifted symplectic stacks (3rd talk in a four-lecture series)
Date:	Wed, Apr 01, 2026, 13:30 - 15:00
Place:	Seminar Room B

MS Seminar (Mathematics - String Theory)

Speaker:	Ben Davison (University of Edinburgh)
Title:	BPS cohomology of (0)-shifted symplectic stacks (2nd talk in a four-lecture series)
Date:	Mon, Mar 30, 2026, 13:30 - 15:00
Place:	Seminar Room A

MS Seminar (Mathematics - String Theory)

Speaker:	Ben Davison (University of Edinburgh)
Title:	BPS cohomology in geometry and representation theory 1 (introductory talk in a four-lecture series)
Date:	Thu, Mar 26, 2026, 15:30 - 17:00
Place:	Seminar Room A
Remarks:	This seminar serves as the introductory talk in a four-lecture series on the same topic. Prof. Ben Davison will give three additional lectures at 13:30 on BPS cohomology of (0)-shifted symplectic stacks at the following venues. Seminar Room A on March 30 (Mon) Seminar Room B on April 1 (Wed) Seminar Room B on April 2 (Thu) In this series of talks I will focus on the theory of cohomological BPS invariants for (0)-shifted symplectic stacks. Although this represents only one of the three options above, there are highly developed applications in geometry, representation theory, and nonabelian Hodge theory, and I will be very happy to take input on which of these directions I should lean towards this second week. Stacks of objects in 2-Calabi-Yau categories are a rich source of (0)-shifted symplectic stacks. The Borel-Moore homology of such stacks carry a cohomological Hall algebra (CoHA) product, and the resulting algebras can be often be described in terms of intersection cohomology of coarse moduli spaces. I will review this theory for Nakajima quiver varieties, where this CoHA can be fairly explicitly described in terms of Borcherds algebras. This leads naturally to a comparison result with the Maulik-Okounkov Yangian, defined in terms of (cohomological) stable envelopes. Focusing more on general theory, there is now (due to joint work with Bu, Ibañéz-Nuñéz, Kinjo and Padurariu) a more general theory of BPS cohomology for (0)-shifted symplectic stacks admitting a good moduli space. This provides the required language for talking about topological mirror symmetry and nonabelian Hodge theory for stacks outside of type A, for example. Finally, BPS cohomology provides the framework for proving cohomological chi-independence type conjectures for enumerative invariants of K3 surfaces. A precise version of this conjecture states that the Gopakumar-Vafa invariants of moduli spaces of 1-dimensional coherent sheaves with primitive Mukai vector on K3 surfaces defined in work of Maulik and Toda, and for generally in further work of Toda, do not depend on the Euler characteristic of the sheaves under consideration. This work requires us to step beyond considering BPS cohomology for fixed abelian categories possessing good moduli spaces, and also provides the natural generalisation of Markman's theorem on tautological generation of the cohomology of moduli spaces of semistable coherent sheaves for primitive Mukai vector.

MS Seminar (Mathematics - String Theory)

Speaker:	José Matos (University of Porto)
Title:	Effective strings and particles interacting in 3D: the Ising model
Date:	Tue, Mar 10, 2026, 15:30 - 17:00
Place:	Seminar Room A

MS Seminar (Mathematics - String Theory)

Speaker:	Vittorio Larotonda (U Bologna)
Title:	A journey through the non-supersymmetric landscape
Date:	Tue, Mar 10, 2026, 13:30 - 15:00
Place:	Seminar Room A
Related File:	3511.pdf

MS Seminar (Mathematics - String Theory)

Speaker:	Federico Ambrosino (Perimeter Institute)
Title:	Perturbed 2d CFT: flows and conserved charges
Date:	Tue, Mar 10, 2026, 11:00 - 12:00
Place:	Lecture Hall
Related File:	3558.pdf

MS Seminar (Mathematics - String Theory)

Speaker:	Tianyu Yuan (Eastern Institute of Technology, Ningbo, China)
Title:	Morse theory on symmetric products and quantized nonabelianization
Date:	Tue, Mar 03, 2026, 15:30 - 17:00
Place:	Seminar Room A

MS Seminar (Mathematics - String Theory)

Speaker:	Francesco Sala (University of Pisa)
Title:	Cohomological Hall algebras of 1-dimensional sheaves and Yangians over the Bridgeland's space of stability conditions
Date:	Tue, Mar 03, 2026, 13:30 - 15:00
Place:	Seminar Room A

MS Seminar (Mathematics - String Theory)

Speaker:	Brandon Rayhaun (Princeton, Institute for Advanced Study (IAS))
Title:	Generalized symmetries of relative QFTs and chiral algebras
Date:	Thu, Feb 26, 2026, 13:30 - 15:00
Place:	Balcony A

MS Seminar (Mathematics - String Theory)

Speaker:	Matthias Gaberdiel (ETHZ)
Title:	Recent advances in AdS3/CFT2
Date:	Tue, Feb 24, 2026, 13:30 - 15:00
Place:	Seminar Room A
Related File:	3498.pdf

MS Seminar (Mathematics - String Theory)

Speaker:	Le Minh Ha (Vietnam Institute for Advanced Study in Mathematics (VIASM))
Title:	Modular Invariant Theory for Polynomial Rings mod Frobenius Powers
Date:	Fri, Feb 20, 2026, 15:30 - 17:00
Place:	Seminar Room B

MS Seminar (Mathematics - String Theory)

Speaker:	Wei Li (ITP-CAS)
Title:	AdS3 Quantum Gravity and Finite N Expansions
Date:	Tue, Feb 10, 2026, 13:30 - 15:00
Place:	Seminar Room A
Related File:	3499.pdf

MS Seminar (Mathematics - String Theory)

Speaker:	Yasuaki Gyoda (Nagoya University)
Title:	Generalized discrete Markov spectra
Date:	Thu, Feb 05, 2026, 15:30 - 17:00
Place:	Seminar Room B

MS Seminar (Mathematics - String Theory)

Speaker:	Lukas Nakamura (IMJ-PRG)
Title:	Gromov-Witten invariants of the Hopf link conormal
Date:	Tue, Feb 03, 2026, 13:30 - 15:00
Place:	Seminar Room A

MS Seminar (Mathematics - String Theory)

Speaker:	Seok Kim (Seoul National University)
Title:	Hairy black holes in AdS
Date:	Tue, Jan 27, 2026, 13:30 - 15:00
Place:	Seminar Room A

MS Seminar (Mathematics - String Theory)

Speaker:	Yuji Odaka (Kyoto University)
Title:	Algebraic aspects of asymptotics of Calabi-Yau/hyperKahler metrics
Date:	Tue, Jan 13, 2026, 15:30 - 17:00
Place:	Seminar Room A

MS Seminar (Mathematics - String Theory)

Speaker:	Reiko Toriumi (OIST)
Title:	Invitation to Random Tensor Models: from random geometry, enumeration of tensor invariants, to characteristic polynomials
Date:	Thu, Jan 08, 2026, 13:30 - 15:00
Place:	Seminar Room B

MS Seminar (Mathematics - String Theory)

Speaker:	Susanne Reffert (University of Bern)
Title:	The large charge expansion for relativistic and non-relativistic physics
Date:	Tue, Jan 06, 2026, 13:30 - 15:00
Place:	Seminar Room A