26-239 Cosmic Census

Mission

Cosmology boasts a successful standard cosmological model. While its success rests on its ability to explain diverse observations, its practical use derives from its framing of open questions. One central open question is: How does the cosmic ecosystem of dark matter and baryons co-evolve? The proposed thesis research will examine this question by modeling the cross-correlation of the Euclid mission’s galaxy and lensing survey with cosmic microwave background (CMB) surveys - the Atacama Cosmology Telescope (ACT), the South Pole Telescope (SPT), and the Simons Observatory (SO). The importance of this question was emphasized by the decadal survey Astro2020, which identified it as one of the three fundamental questions for the coming decade in astrophysical research. 

The mystery at the heart of this question is why only 10% of baryons (ordinary atoms) end up in stars, the stellar mass in galaxies, by today. Left alone, the majority of baryons would...