Galaxy imaging surveys as spin-sensitive detector for cosmological colliders

Understand

Galaxy imaging surveys provide us with information on both the galaxy distribution and their shapes.

• In this paper, we systematically investigate the sensitivity of galaxy shapes to new physics in the initial conditions.
• For this purpose, we decompose the galaxy shape function into spin components, and compute the contributions to each spin component from both intrinsic alignment and weak lensing.
• We then consider the angular-dependent primordial non-Gaussianity, which is generated by a non-zero integer spin particle when active during inflation, and show that a galaxy imaging survey essentially functions as a spin-sensitive detector of such particles in the early universe.