Galaxy shapes as a cosmological tool

Two phenomena contribute to correlating galaxy shapes across the Universe: the deviation of photons from a straight path due to the spacetime curvature ("gravitational lensing”), and tidal interactions (“intrinsic alignments”). Modeling both accurately is crucial to obtaining unbiased constraints on the cosmological model from forthcoming surveys, particularly in the context of elucidating the origin of accelerated expansion of the Universe. In this talk, I will cover recent advances in our understanding of the intrinsic alignments of galaxies. While these alignments are typically regarded as a contaminant to weak gravitational lensing, I will also discuss how they might become a cosmological and astrophysical probe in their own right in the near future.