Galaxy environments and graph neural networks

This post discusses how graph neural networks (GNNs) can model the galaxy–halo connection within its large-scale surroundings. Dark matter structures, which seem to account for most of the mass in the Universe, can be represented as nodes in a cosmic graph. But dark matter—which solely interacts via gravitation—is also much easier to simulate than the messy baryons, whose magnetohydrodynamics are…