Conferences This Week and Next Week

Seminars This Week and Next Week

Special Seminar (Astro Seminar)

Speaker:	Géza Csörnyei
Title:	SNe II the rescue: independent determination of the Hubble constant through spectral modeling of Type II supernovae
Date:	Wed, Mar 25, 2026, 11:00 - 12:00
Place:	Seminar Room A

APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker:	Sara Bianco (DESY)
Title:	BBN disintegration limits from ν-injections
Date:	Wed, Mar 25, 2026, 13:30 - 15:00
Place:	Seminar Room A

Special Seminar (fundamentals seminar)

Speaker:	Luca Marchetti (Kavli IPMU)
Title:	Background Independence: What Is Observable in Gravity, and How Do We Quantize It?
Date:	Wed, Mar 25, 2026, 15:30 - 17:00
Place:	Seminar Room A
Remarks:	It is only in person.

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.

APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker:	Nathalie Korhonen Cuestas (NorthWestern University)
Title:	Metallicity Scaling Relations at Cosmic (after)Noon
Date:	Mon, Mar 30, 2026, 11:00 - 12:00
Place:	Seminar Room A

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

APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker:	David Sanders (Univ. of Hawaii, Institute of Astronomy)
Title:	The Origin and Evolution of Luminous AGN: recent progress and future challenges
Date:	Tue, Mar 31, 2026, 15:30 - 17:00
Place:	Seminar Room A

APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker:	Serguey T. Petcov (INFN/SISSA)
Title:	Modular-Symmetry-Protected Seesaw Mechanism
Date:	Wed, Apr 01, 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 (3rd talk in a four-lecture series)
Date:	Wed, Apr 01, 2026, 13:30 - 15:00
Place:	Seminar Room B

APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker:	Aaron Vincent (Queen's U)
Title:	TBA
Date:	Thu, Apr 02, 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

APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker:	Henrique Rubira (Cambridge/LMU)
Title:	TBA
Date:	Fri, Apr 03, 2026, 15:30 - 17:00
Place:	Seminar Room A