Correlation functions from a unified variational principle: trial Lie groups

TL;DR

This paper introduces a unified variational principle to compute time-dependent expectation values and correlation functions in many-body quantum systems, providing a systematic approach to evaluate these quantities.

Contribution

It develops a novel variational framework based on trial Lie groups that unifies the calculation of expectation values and correlation functions in quantum many-body physics.

Findings

Provides a new method for calculating correlation functions.

Demonstrates the effectiveness of the variational principle in quantum systems.

Offers a systematic approach to time-dependent quantum observables.

Abstract

Time-dependent expectation values and correlation functions for many-body quantum systems are evaluated by means of a unified variational principle. It optimizes a generating functional depending on sources associated with the observables of interest $\ldots$