Green Templeton's annual Ceilidh is in our building again this year on the evening of Friday 24th January at 9.30 pm and we have been reserved 30 free tickets which you can access using the following link and access code.
Burns Night Tickets[ Code: GTCMATHS25
Please use your maths email addresses when booking tickets.
16:00
Continuity of heights and complete intersections in toric varieties
Abstract
I will describe the contents of a joint project with Pablo Destic and Nuno Hultberg. In the paper we confirm a conjecture of Roberto Gualdi regarding a formula for the average height of the intersection of twisted (by roots of unity) hyperplanes in a toric variety. I will introduce the 'GVF analytification' of a variety, which is defined similarly as the Berkovich analytification, but with norms replaced by heights. Moreover, I will discuss some motivations coming from (continuous) model theory and Arakelov geometry.
A new axiom for Q_p^ab and non-standard methods for perfectoid fields
Abstract
The class of henselian valued fields with non-discrete value group is not well-understood. In 2018, Koenigsmann conjectured that a list of seven natural axioms describes a complete axiomatisation of Q_p^ab, the maximal extension of the p-adic numbers Q_p with abelian Galois group, which is an example of such a valued field. Informed by the recent work of Jahnke-Kartas on the model theory of perfectoid fields, we formulate an eighth axiom (the discriminant property) that is not a consequence of the other seven. Revisiting work by Koenigsmann (the Galois characterisation of Q_p) and Jahnke-Kartas, we give a uniform treatment of their underlying method. In particular, we highlight how this method yields short, non-standard model-theoretic proofs of known results (e.g. finite extensions of perfectoid fields are perfectoid).
15:30