Probing the Cosmic Energy Density Inventory with Tomographic Intensity Mapping
The formation of stars, galaxies, and the large-scale structure in the Universe drives complex energy density flows over a wide range of scales from atomic nuclei to the Hubble length. The net effect could be summarized by a census of the density parameters, Ω, for different entries of the cosmic inventory over time. I will talk about my ongoing effort to probe the history of some key cosmic constituents, including stars, dust, thermal and gravitational energy associated with the large-scale structure. These are constrained via intensity mapping of the cosmic UV, IR, and the Sunyaev-Zeldovich effect backgrounds tomographically as functions of redshift via a new clustering-based technique. While these measurements are already pushing our understanding of the Universe, they represent only the beginning of a new chapter of observational cosmology using the entire radiation field as opposed to only detectable bright galaxies. I will conclude by sharing my excitement on the future prospects of extragalactic background intensity mapping.