Introduction

This section collects machine-learning tutorials on universal relations for neutron stars, with examples ranging from rapidly rotating configurations to neural-network descriptions of stellar surfaces and higher-order multipole relations.

The material is drawn from three tutorial repositories:

• UR-for-rotating-NS-using-ML-: universal relations for rapidly rotating neutron stars.

• Universal-description-of-the-NS-surface-using-ML: neural-network regressors for neutron-star surface quantities.

• deep-universal-relations: deep-learning models for universal relations involving moments of inertia, quadrupole moments, spin octupoles, and related quantities.

The notebooks are provided by Grigorios Papigkiotis and Georgios Vardakas.