Department of Mathematics and Computer Science

Speaker: Pallav Goyal (​University of Southern Denmark).Abstract: Ringel used the Hall algebra of a quiver to construct the positive half of the quantised enveloping algebra of the corresponding Kac–Moody algebra, and Lusztig’s geometric version of this construction produced canonical bases of these positive halves having remarkable positivity properties. A limitation of this approach is that it only yields the positive half of the algebra.This phenomenon is ubiquitous in the field: ‘halves’ of many non-commutative algebras (quantum groups, toroidal algebras, DAHAs, etc.) have been obtained as Hall algebras, but examples of ‘entire’ algebras being realised intrinsically are rare. I will survey some previous work on this problem and then describe joint work with Peter Samuelson giving complete Hall-theoretic realisations of several classes of quantum algebras, including shifted quantum affine algebras and quantum coordinate rings of matrices.

Devon Stockall defends his PhD thesis at a public lecture: “Defects and Interfaces in Topological Sigma Models via Higher Sheaf Theory”.Associate Professor Matthias Oliver Wilhelm will serve as chairman of the defence.The PhD defence takes place in IMADA Conference Room (Ø18-509-2).All are welcome.

Speaker: Benjamin Shackleton (​University of Southern Denmark).Abstract: In this pre-PhD work, completed with input from Professor Sir Simon Donaldson and Dr Daniel Platt, I prove the existence of a Ricci flat metric on the Kummer K3 surface. The proof follows the general strategy of Donaldson’s gluing construction. However, we tackle the analysis without appealing to weighted norms or conformal transformations to model spaces, instead relying solely on compact elliptic theory on usual Hölder and Sobolev spaces.The talk will coversetting up the problem and the computation of the estimates used.The paper can be found here: https://arxiv.org/abs/2605.02046.

Speaker: Shing Tak Lam (​University of Warwick).Abstract: TBA

Students develop a wide range of competences throughout their education, but they do not always recognise everything they become better at along the way.

Muhammad Rajabinasab defends his PhD thesis at a public lecture: “Explanation as an Act of Selection: Feature Selection, Explainable AI, and Evaluation in Machine Learning”.The chairman of the assessment committee, Professor Melih Kandemir, will act as chairman at the defence.The PhD defence takes place in IMADA Conference Room (Ø18-509-2).All are welcome.

Speaker: Apoorv Tiwari (​University of Southern Denmark).Abstract: TBA

Speaker: Arim Song (​Friedrich-Alexander University Erlagen-Nürnberg).Abstract: TBA