Model reduction methods for nuclear emulators

The field of model order reduction (MOR) is growing in importance due to its ability to extract the key insights from complex simulations while discarding computationally burdensome and superfluous information. We provide an overview of MOR methods for the creation of fast & accurate emulators of memory- and compute-intensive nuclear systems, focusing on eigen-emulators and variational emulators. As an example, we describe how 'eigenvector continuation' is a special case of a much more general and well-studied MOR formalism for parameterized systems. We continue with an introduction to the Ritz and Galerkin projection methods that underpin many such emulators, while pointing to the relevant MOR theory and its successful applications along the way. We believe that this guide will open the door to broader applications in nuclear physics and facilitate communication with practitioners in other fields.

Automated summary

The article provides an overview of the application of model order reduction (MOR) in fast and accurate emulators for nuclear systems. It focuses on eigen-emulators and variational emulators, and offers guidance on the relevant MOR theory and successful applications.