Efficient emulators for scattering using eigenvector continuation

TL;DR

This paper extends eigenvector continuation to scattering problems, demonstrating it as an efficient and accurate emulator for various scattering scenarios, enabling Bayesian parameter inference with minimal computational cost.

Contribution

The paper introduces a novel extension of eigenvector continuation to scattering, validating its effectiveness across multiple complex scattering cases.

Findings

Accurately reproduces scattering observables with few basis vectors

Works for non-local, charged-particle, and complex optical potentials

Enables efficient Bayesian inference for scattering parameters

Abstract

Eigenvector continuation EC has been shown to accurately and efficiently reproduce ground states for targeted sets of Hamiltonian parameters. It uses as variational basis vectors the corresponding ground-state eigensolutions from selected other sets of parameters. Here we extend the EC approach to scattering using the Kohn variational principle. We first test it using a model for S-wave nucleon-nucleon scattering and then demonstrate that it also works to give accurate predictions for non-local potentials, charged-particle scattering, complex optical potentials, and higher partial waves. These proofs-of-principle validate EC as an accurate emulator for applying Bayesian inference to parameter estimation constrained by scattering observables. The efficiency of such emulators is because the accuracy is achieved with a small number of variational basis elements and the central computations are just linear algebra calculations in the space spanned by this basis.