Galaxies on Graph Neural Networks

The current accelerated expansion of the Universe is driven by mysterious dark energy. Upcoming astronomical imaging surveys, such as LSST at Rubin Observatory, are set to provide unprecedented precise measurements of cosmological parameters, including this dark energy, using measurements such as weak gravitational lensing. Weak lensing is measured by looking for coherent patterns in galaxy shapes, which can be caused by the fact that the cosmic matter distribution coherently distorts spacetime, affecting the appearances of nearby galaxy images in similar ways. However, there are still challenges facing cosmologists on their path from data to science. One of these challenges is the effect of intrinsic alignments – where galaxies are not oriented randomly in the sky, but rather tend to point towards other galaxies.