# Relaxation theory for perturbed many-body quantum systems versus numerics and experiment

## TL;DR

This paper develops an analytical framework to predict how isolated many-body quantum systems relax to thermal equilibrium under small perturbations, validated by numerical and experimental comparisons.

## Contribution

It introduces a typicality-based analytical prediction method for quantum relaxation under perturbations, bridging theory with numerical and experimental results.

## Key findings

- Analytical predictions match numerical simulations
- Predictions agree with experimental observations
- Most perturbations lead to similar relaxation behavior

## Abstract

An analytical prediction is established of how an isolated many-body quantum system relaxes towards its thermal long-time limit under the action of a time-independent perturbation, but still remaining sufficiently close to a reference case whose temporal relaxation is known. This is achieved within the conceptual framework of a typicality approach by showing and exploiting that the time-dependent expectation values behave very similarly for most members of a suitably chosen ensemble of perturbations. The predictions are validated by comparison with various numerical and experimental results from the literature.