Yang-Mills form factors on self-dual backgrounds
Bogna, G Mason, L Journal of High Energy Physics volume 2023 issue 8 165 (24 Aug 2023)
Mon, 16 Oct 2023
15:30
Lecture Theatre 3, Mathematical Institute, Radcliffe Observatory Quarter, Woodstock Road, OX2 6GG

Non-adversarial training of Neural SDEs with signature kernel scores

Dr Maud Lemercier
(Mathematical Institute (University of Oxford))
Further Information

Please join us from 1500-1530 for tea and coffee outside the lecture theatre before the talk.

Abstract

Neural SDEs are continuous-time generative models for sequential data. State-of-the-art performance for irregular time series generation has been previously obtained by training these models adversarially as GANs. However, as typical for GAN architectures, training is notoriously unstable, often suffers from mode collapse, and requires specialised techniques such as weight clipping and gradient penalty to mitigate these issues. In this talk, I will introduce a novel class of scoring rules on path space based on signature kernels and use them as an objective for training Neural SDEs non-adversarially. The strict properness of such kernel scores and the consistency of the corresponding estimators, provide existence and uniqueness guarantees for the minimiser. With this formulation, evaluating the generator-discriminator pair amounts to solving a system of linear path-dependent PDEs which allows for memory-efficient adjoint-based backpropagation. Moreover, because the proposed kernel scores are well-defined for paths with values in infinite-dimensional spaces of functions, this framework can be easily extended to generate spatiotemporal data. This procedure permits conditioning on a rich variety of market conditions and significantly outperforms alternative ways of training Neural SDEs on a variety of tasks including the simulation of rough volatility models, the conditional probabilistic forecasts of real-world forex pairs where the conditioning variable is an observed past trajectory, and the mesh-free generation of limit order book dynamics.

Four point functions in CFT’s with slightly broken higher spin symmetry
Silva, J Journal of High Energy Physics volume 2021 issue 5 97 (12 May 2021)
Nonperturbative Mellin amplitudes: existence, properties, applications
Penedones, J Silva, J Zhiboedov, A Journal of High Energy Physics volume 2020 issue 8 31 (06 Aug 2020)
Applications of dispersive sum rules: $ε$-expansion and holography
Carmi, D Penedones, J A. Silva, J Zhiboedov, A SciPost Physics volume 10 issue 6 145 (14 Jun 2021)
Photo of Artur

Oxford Mathematician Artur Ekert has been awarded the Milner Award and Lecture by the Royal Society for "pioneering contributions to quantum communication and computation, which transformed the field of quantum information science from a niche academic activity into a vibrant interdisciplinary field of industrial relevance."

Supporting data for the paper "Asymmetric periodic boundary conditions for all-atom molecular dynamics and coarse-grained simulations of nucleic acids"
Erban, R Togashi, Y
Asymmetric periodic boundary conditions for all-atom molecular dynamics and coarse-grained simulations of nucleic acids
Erban, R Togashi, Y Journal of Physical Chemistry B (Soft Condensed Matter and Biophysical Chemistry) volume 127 issue 38 8257-8267 (15 Sep 2023)
Equivariant localization in supergravity
Benetti Genolini, P Gauntlett, J Sparks, J Physical Review Letters volume 131 issue 12 (18 Sep 2023)
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Oxford Mathematics Public Lecture - Four Ways of Thinking: Statistical, Interactive, Chaotic and Complex - David Sumpter

Mathematics is about finding better ways of reasoning. But for many applied mathematicians, the primary mission is to shape their minds in a way that gets them closer to the truth. The calculations are secondary, the real question is: how we can better understand the world around us?

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