Joint Astrophysical Colloquium
Learning about the very early Universe from galaxies and QSOs
Violeta Hernandez (UAM)
Thursday 05/03/2026 @ 11:30, Sala Antonio Sollima (IV piano Battiferro)
What happened to the universe between its beginning with the Big Bang and its first light? Answering this question is no easy task, as we are currently unable to take direct measurements from that era. The theory that best describes the first moments of the universe's evolution is the theory of inflation. This theory proposes that the universe went from being the size of a proton to the size of the solar system in a fraction of a second. The mechanisms that can produce such expansion are unclear. Some of the proposed mechanisms leave a trace that can be measured from the distribution of galaxies in the observable universe. Several international collaborations, such as DESI and Euclid, are creating 3D maps of the Universe. These maps will allow us to explore which inflation theories are viable. In order to reach such conclusions, we need to use enormous numerical simulations that generate catalogues of galaxies in volumes comparable to that of the observable universe. We have made publicly available the UNIT universes that we have generated to study the early universe through the distribution of matter at late cosmic times (https://opendata.pic.es/unitsim/). In this talk I will present our methodology and our finding so far.