The Long Journey from Ab Initio Calculations to Density Functional Theory for Nuclear Large Amplitude Collective Motion

TL;DR

This paper explores the connection between ab initio Density Functional Theory and functional integral approaches for modeling large amplitude collective motion in nuclear physics, proposing a stochastic DFT framework to unify these methods.

Contribution

It introduces a stochastic time-dependent DFT approach aiming to bridge the gap between DFT and functional integral methods for nuclear many-body dynamics.

Findings

Analysis of DFT limitations in Large Amplitude Collective Motion

Discussion of functional integral advantages for observable calculations

Proposal of a stochastic DFT framework to unify approaches

Abstract

At present there are two vastly different ab initio approaches to the description of the the many-body dynamics: the Density Functional Theory (DFT) and the functional integral (path integral) approaches. On one hand, if implemented exactly, the DFT approach can allow in principle the exact evaluation of arbitrary one-body observable. However, when applied to Large Amplitude Collective Motion (LACM) this approach needs to be extended in order to accommodate the phenomenon of surface-hoping, when adiabaticity is strongly violated and the description of a system using a single (generalized) Slater determinant is not valid anymore. The functional integral approach on the other hand does not appear to have such restrictions, but its implementation does not appear to be straightforward endeavor. However, within a functional integral approach one seems to be able to evaluate in principle any kind of observables, such as the fragment mass and energy distributions in nuclear fission. These two radically approaches can likely be brought brought together by formulating a stochastic time-dependent DFT approach to many-body dynamics.