GDR CoPhy Episode 4

Session

Tuesday Morning

2 juin 2026, 10:50

Clermont Ferrand

42. Testing Entropic Explanations of Cosmic Acceleration with DESI and Supernovae

Soumen Basak (IISER Thiruvananthapuram, Kerala, India)

02/06/2026 10:50

The accelerated expansion of the Universe is usually described by a cosmological constant, $\Lambda$. An interesting alternative idea is entropic cosmology, where the entropy associated with the cosmic horizon effectively contributes to (or mimics) dark energy. In this talk, I will compare two commonly discussed routes: (i) holographic dark energy (HDE), where the dark-energy density is tied...

43. The Secret Life of Voids: Unifying Density Profiles and their Evolution

Nico SCHUSTER (CPPM)

02/06/2026 11:20

Cosmic voids occupy the majority of the Universe’s volume and are dominated by dark energy at earlier times, making them one of the most promising probes for current and upcoming surveys. However, fully exploiting this potential requires a robust understanding of their evolution and modeling. We track the history of halo-defined voids from z = 5 to the present day using hydrodynamical...

46. How to measure cosmology from nothing: void-galaxy cross-correlation with DESI

Katayoon GHAEMI (Centre de Physique des Particules de Marseille (CPPM))

02/06/2026 11:50

Cosmic voids provide a novel probe of structure formation and cosmic expansion. They are sensitive to structure growth, dark energy, modified gravity, and sum of neutrino masses. Using the DESI spectroscopic data, we perform void identification and present the preliminary measurements of the void-galaxy cross-correlation function. By measuring the void-galaxy cross-correlation function we can...