University of Bristol: Friday 16th January, 2026

Directions: From Bath Spa station, you can either take the U1 bus at the front (~20 minutes from the station to campus, buses come every ~15 minutes), or you can walk (45-50 minutes, steep uphill). See the University's "how to get here" page for more details

Lecture room: We will be in 4 West, Lecture Room 1.2 on the ground floor. See the campus map for directions. Note that you can enter 4 West from the parade, and then you go down the stairs


Registration is now closed

 

Directions: From Temple Meads train station, you can either take the 8/72 buses at the front to the top of Park Street (~20 minutes from the station, buses come frequently), or you can walk (30-45 minutes, largely uphill). See the University's "how to get here" page for more details.

Lecture room: We will be in the Fry Building, Lecture Room 2.04 on the second floor. See the campus map for directions.

 

Schedule:

Speakers:

Alex Bartel (University of Glasgow)

Title: Isospectral manifolds via orders in quaternion algebras

Abstract: I will report on joint work with Aurel Page on a number/representation theoretic approach to the question "Can you hear the shape of a drum". We use quaternion algebras over number fields to construct pairs of manifolds that "sound the same", but differ from each other in subtle ways. I will not assume that you already care about this question.

Jordan Docking (King's College London)

Title: Reduction of Plane Quartic Curves and Cayley Octads

Abstract: In this talk, we'll discuss stable models of plane quartic curves over local fields, and their relationship with Cayley octads, geometric objects coming from the even theta-characteristics of these curves. In particular, we'll consider how degenerations in the Cayley octad produce a classification of such models, as well as how this parallels the cluster picture machinery for hyperelliptic curves. This talk is based on joint work with Ramyond van Bommel, Vladimir Dokchitser, Elisa Lorenzo García, Reynald Lercier and Andreas Pieper.

Katerina Santicola (University of Bath)

Title: Number fields with prescribed ramification featuring the stack BG.

Abstract: The inverse Galois problem has many refinements. In this talk, we focus on the existence of Galois extensions with restricted ramification. The Gras--Munnier formula provides a quick test for whether such extensions exist. We discuss how the Gras--Munnier formula corresponds to a Brauer--Manin obstruction to strong approximation on the classifying stack BG. 

Besfort Shala (University of Bristol)

Title: Mixed character sums

Abstract: I will talk about a distributional result for 'mixed character sums', which are exponential sums with multiplicative coefficients given by values of a Dirichlet character. As a deterministic application, we construct polynomials with coefficients +1 and -1 with large Mahler measure, establishing a new record in Mahler's problem. This is joint work with Jonathan W. Bober and Oleksiy Klurman.