MetaFun: Meta-learning with iterative functional updates
Xu, J Ton, J Kim, H Kosiorek, A Teh, Y 37th International Conference on Machine Learning, ICML 2020 volume PartF168147-14 10548-10558 (01 Jan 2020)
Fractional underdamped langevin dynamics: Retargeting SGD with momentum under heavy-tailed gradient noise
Simsekli, U Zhu, L Teh, Y Gürbüzbalaban, M 37th International Conference on Machine Learning, ICML 2020 volume PartF168147-12 8917-8927 (01 Jan 2020)
Effectiveness and resource requirements of test, trace and isolate strategies for COVID in the UK
He, B Zaidi, S Elesedy, B Hutchinson, M Paleyes, A Harling, G Johnson, A Teh, Y group, O Royal Society Open Science volume 8 issue 3 201491 (24 Mar 2021)
Mon, 24 May 2021
14:00
Virtual

RG Flows and Bounds from Chaos

Sandipan Kundu
(JHU)
Abstract

I will discuss a precise connection between renormalization group (RG) and quantum chaos. Every RG flow between two conformal fixed points can be described in terms of the dynamics of Nambu-Goldstone bosons of broken symmetries. The theory of Nambu-Goldstone bosons can be viewed as a theory in anti-de Sitter space with the flat space limit. This enables an equivalent formulation of these 4d RG flows in terms of spectral deformations of a generalized free CFT in 3d. This approach provides a precise relation between C-functions associated with 4d RG flows and certain out-of-time-order correlators that diagnose chaos in 3d. As an application, I will show that the 3d chaos bound imposes constraints on the low energy effective action associated with unitary RG flows in 4d with a broken continuous global symmetry in the UV. These bounds, among other things, imply that the proof of the 4d a-theorem remains valid even when additional global symmetries are broken.

Born out of lockdown in 2020, the Oxford Mathematics Online Exhibition might just have become a permanent fixture in our mathematical lives.

We ask all our Oxford Mathematicians, young and less young, to come up with art that expresses a mathematical idea in the form of their choice.

Image to the right: Joel Madly - Triangular mesh with fractal behaviour (click to see full detail)

Image below: Andrew Krause - Turing Pattern Faces (click to see full detail)

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Adaptive formal approximations of Markov chains
Abate, A Andriushchenko, R Ceska, M Kwiatkowska, M Palmer, T Performance Evaluation volume 148 (19 Apr 2021)
Balancing expressiveness and inexpressiveness in view design
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Stein's Method Meets Statistics: A Review of Some Recent Developments
Anastasiou, A Barp, A Briol, F Ebner, B Gaunt, R Ghaderinezhad, F Gorham, J Gretton, A Ley, C Liu, Q Mackey, L Oates, C Reinert, G Swan, Y
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