The Large-Scale Structure of the Universe is seeded by small quantum fluctuation generated during inflation. Small density fluctuations were inflated to cosmological scales. Later, when the Universe was formed by a hot plasma, sound waves propagated this overdensities up to the era of decoupling. As the Universe becomes neutral, the sound-wave pattern gets frozen, leaving a prefered scale in the distribution of matter in the Universe: the sound horizon at this time. This pattern, the Baryonic Acoustic Oscillations (BAO), can be found by looking at the overdensity of galaxies.
The Dark Energy Survey was designed as a multi-probe experiment to constrain Dark Energy properties and other cosmological parameters. For that, it surveyed one eighth of the sky over 6 years in 5 bands, detecting hundreds of millions of galaxies with a state-of-the-art camera, partially constructed at IFAE.
One of the main cosmological probes is the measurement of BAO. Here we present the BAO measurement from the final dataset using a subsample of 16 million galaxies at an epoch when the universe had half of its current age
Giada Caneva, Elia Bertoldo, Francesco Sciotti