Testing fundamental physics with cosmological large-scale structure (LSS) across cosmic times

The LSS is formed under the influence of gravity from tiny fluctuations generated during the very early Universe. As such, it contains invaluable information about the origin, evolution, and constituents of the Universe, offering unique opportunities to test fundamental physics across cosmic history. Detection of individually resolved galaxies, as done in galaxy redshift surveys, and measurement of aggregate light from an ensemble of galaxies or intergalactic medium, as performed in line intensity mapping (LIM), are two observational techniques to map the LSS. While the former is now a relatively mature field with several upcoming surveys (e.g., DESI and Euclid) expected to provide an unprecedented volume of high-precision data, the latter is still an emerging field, with future surveys currently in the planning stage. In the first part of this talk, I will discuss the importance of employing summary statistics beyond the two-point correlation functions to capture the non-Gaussian information encoded in the LSS. Extraction of this information is particularly relevant for fully realizing the potential of upcoming galaxy surveys in testing fundamental physics. In the second part of the talk, I will illustrate the promise of LIM in shedding light on key open questions in cosmology by mapping the LSS over unprecedented cosmic volumes, including ultra-large scales and high redshifts. I will describe essential ingredients in accurately modeling the LIM signal and discuss an example of powerful synergies between LIM and other cosmological observations.