Title: Fast & accurate emulation using reduced-basis methods

 

Abstract:

The challenges of nuclear many-body physics have been addressed theoretically with a wide range of accurate but often computationally expensive methods. However, when we need to change the parameters characterizing the problem, such as Hamiltonian coupling constants, it can become computationally prohibitive to repeat calculations many times and challenging to reliably extrapolate. An alternative is to replace the expensive model with an *emulator*, which is an approximate computer model. In this colloquium we describe the recent development of emulators that exploit a technique called eigenvector continuation (EC); this is an adaptation of so-called reduced-basis methods used widely in engineering applications. There has been an explosion of EC applications in the last few years to nuclear structure and reactions, but the methods are broadly applicable to physics problems and can be illustrated with basic quantum mechanics.