Congratulations to Ulrike who has received an honorary doctorate from the University of Copenhagen.
Ulrike is a Professor of Mathematics here in Oxford specialising in algebraic topology and also Director of the Isaac Newton Institute in Cambridge.
TRACKING SINUSOIDAL SIGNALS WITH TIME VARYING FREQUENCY USING OPTIMAL CONTROL
Evans, R
Liu, C
Nair, G
Suvorova, S
Moran, B
Communications in Optimization Theory
volume 2025
(01 Jan 2025)
Dynamic Length FSK Waveforms for Joint Communications and Radar
Han, T
Smith, P
Mitra, U
Evans, J
Evans, R
Senanayake, R
IEEE Transactions on Wireless Communications
(01 Jan 2025)
Broadband Flexible Sensor for Microwave Dielectric Spectroscopy of Liquids in Vials
Harkinezhad, B
Markovic, T
Evans, R
Ghorbani, K
Skafidas, E
Schreurs, D
IEEE Transactions on Microwave Theory and Techniques
(01 Jan 2025)
Drift-Diffusion Equations with Saturation
Carrillo, J
Fernández-Jiménez, A
Gómez-Castro, D
SIAM Journal on Mathematical Analysis
volume 57
issue 6
6300-6360
(31 Dec 2025)
The Green Friday campaign offers a 15% discount on all Oxford Merchandise gear. Additionally, for every order placed using the discount code GREEN15, The College Store will again plant two trees instead of one. To date they have planted over 5,700 trees as a direct result from orders through the store.
The discount will run from November 21 until December 1.
Mon, 17 Nov 2025
16:00
16:00
C3
Special L-values and Non-split Extensions of Hodge Structures
Michael Cheng
(University of Oxford)
Abstract
The Deligne-Beilinson conjecture predicts that the special values of many L-functions are related to the ranks of certain Ext groups in the category of mixed Hodge structures. In this talk, we present Skinner’s constructions of certain extensions that are extracted from the cohomology of the modular curve using CM points and the Eisenstein series. Through an explicit analytic calculation, which is performed in the adelic setting using (g,K)-cohomology and Tate’s zeta integrals, we obtain a formula relating the non-triviality of these extensions to the well-known non-vanishing at s=1 of the L-functions associated to Hecke characters of imaginary quadratic fields. These constructions have natural analogs in the category of p-adic Galois representations which are useful for Euler systems.