Theory Seminars

Nina Elmer (U Cambridge), "From Amplitudes to PDFs: Uncertainty-Aware ML"

Europe/Amsterdam
Veltman Centre

Veltman Centre

Description

Machine learning (ML) is becoming an increasingly powerful tool in particle physics, offering fast surrogates for expensive theoretical calculations and flexible methods for analysing complex, high-dimensional data. For precision applications, however, accurate predictions alone are not sufficient. They must be accompanied by reliable uncertainty estimates.

In this talk, I will discuss uncertainty-aware ML in controlled-theory settings, starting with neural-network surrogates for scattering amplitudes. With known target functions, amplitudes provide a clean benchmark for studying calibrated uncertainties, artificial noise, training-data gaps, and biases. I will then move on to a more complex inverse problem using a non-singlet PDF distribution as a controlled example, in which the target is inferred via a physics forward map rather than observed directly. I will compare neural-network ensembles, Gaussian processes, and neural tangent kernels as tools for uncertainty estimation and extrapolation.