Generative Flow Networks for Model Adaptation in Digital Twins of Natural Systems

TL;DR

This paper introduces a GFlowNet-based method for adapting models in digital twins of natural systems, enabling sampling of plausible configurations under uncertainty.

Contribution

It formulates model adaptation as a generative problem over simulator parameters, improving sampling of diverse plausible configurations.

Findings

Recovers dominant adaptation regions in a case study

Retrieves strong calibration hypotheses

Preserves multiple plausible configurations under uncertainty

Abstract

Digital twins of natural systems must remain aligned with physical systems that evolve over time, are only partially observed, and are typically modeled by mechanistic simulators whose parameters cannot be measured directly. In such settings, model adaptation is naturally posed as a simulation-based inference problem. However, sparse and indirect observations often fail to identify a unique and optimal calibration, leaving several simulator parameterizations compatible with the available evidence. This article presents a GFlowNet-based approach to model adaptation for digital twins of natural systems. We formulate adaptation as a generative modeling problem over complete simulator configurations, so that plausible parameterizations can be sampled with probability proportional to a reward derived from agreement between simulated and observed behavior. Using a controlled environment agriculture case study based on a mechanistic tomato model, we show that the learned policy recovers dominant regions of the adaptation landscape, retrieves strong calibration hypotheses, and preserves multiple plausible configurations under uncertainty.