Choose timezone
Your profile timezone:
Sezione
HEP Colloquia 2026
by
→
Europe/Rome
Sala Consiliare (Department of Physics)
Sala Consiliare
Department of Physics
Description
Detection of anisotropic cosmic structures on a gigaparsec scale
Galaxy surveys allow us to test one of the deepest assumptions in modern cosmology: that, on sufficiently large scales, the Universe becomes statistically uniform and looks the same in every direction. In the standard model, the cosmic web of galaxies, filaments, walls and voids should gradually lose its directional structure on very large scales.
In this talk, I will present the results reported in 10.1038/s41586-026-10702-5. In particular , I will discuss the evidence from the first DESI data release that this transition may not happen as quickly as expected. Using the Angular Distribution of Pairwise Distances, a parameter-free statistic that measures whether galaxy pairs preferentially align along particular directions, we find coherent directional patterns extending to scales of order one gigaparsec. These signals are stronger than those found in isotropic controls and in geometry-matched ΛCDM mock catalogues, with conservative significances greater than 3σ.
I will explain the method, show how the signal appears in DESI galaxy samples, and discuss what these results could imply for the cosmological principle, the growth of cosmic structure, and possible new physics in the dark sector or gravity.
In this talk, I will present the results reported in 10.1038/s41586-026-10702-5. In particular , I will discuss the evidence from the first DESI data release that this transition may not happen as quickly as expected. Using the Angular Distribution of Pairwise Distances, a parameter-free statistic that measures whether galaxy pairs preferentially align along particular directions, we find coherent directional patterns extending to scales of order one gigaparsec. These signals are stronger than those found in isotropic controls and in geometry-matched ΛCDM mock catalogues, with conservative significances greater than 3σ.
I will explain the method, show how the signal appears in DESI galaxy samples, and discuss what these results could imply for the cosmological principle, the growth of cosmic structure, and possible new physics in the dark sector or gravity.
Organized by
Prof. Umberto D'Alesio - umberto.dalesio@ca.infn.it
Dr. Nanako Kato - nanako.kato@dsf.unica.it
Contact