Tuesday, 3 October 2023, 4-5pm Location: 24 Gordon Square Room 105

• Speaker: Ian Griffiths (Oxford)
  
  Title: How can mathematics help us keep the world clean?
  
  Abstract:
World cleaning applies to air, water and land: In the wake of the pandemic and the potential for future pandemics, how can we predict the risk of catching a virus in an indoor setting and how do antiviral air purifiers mitigate this risk?; The continued increase in water scarcity prompts us to seek better ways of providing clean water; And the novichok chemical warfare incident in 2018 motivates questions on how one adequately cleans up a chemical spill. In this talk, we use a variety of mathematical modelling techniques - some simple, others more complicated - to provide answers to these questions and others as we seek strategies to keep our world clean.

Tuesday, 21 November 2023, 4-5pm Location: Medical Sciences - G46 H O Schild Pharmacology LT

• Speaker: Codina Cotar (UCL)
  
  Title: Disorder relevance for non-convex random gradient Gibbs measures in d=2
  
  Abstract: It is a famous result of statistical mechanics that, at low enough temperature, the random field Ising model is disorder relevant for d=2, i.e. the phase transition between uniqueness/non-uniqueness of Gibbs measures disappears, and disorder irrelevant otherwise (Aizenman-Wehr 1990). Generally speaking, adding disorder to a model tends to destroy the non-uniqueness of Gibbs measures. In this talk we consider - in non-convex potential regime - a random gradient model with disorder in which the interface feels like a bulk term of random fields. We show that this model is disorder relevant with respect to the question of uniqueness of gradient Gibbs measures for a class of non-convex potentials and disorders. We also discuss the question of decay of covariances for the model. No previous knowledge of gradient models will be assumed in the talk. This is joint work with Simon Buchholz.

Tuesday, 5 December 4-5pm Location: Medical Sciences - G46 H O Schild Pharmacology LT

• Speaker: Jon Keating (Oxford)
  
  Title: Moments of Characteristic Polynomials of Random Unitary Matrices
  
  Abstract:I will review results relating to certain generalised moments of the characteristic polynomials of random unitary matrices and their connections to the value distribution of the Riemann zeta-function on its critical line.

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You'll find the old colloquium schedules here.