GDR CoPhy Episode 4

Session

Tuesday Morning

2 juin 2026, 11:00

Clermont Ferrand

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

Soumen Basak (IISER Thiruvananthapuram, Kerala, India)

02/06/2026 11:00

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 11:30

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...

44. The shape of emptiness: improving the signal from cosmic voids using reconstruction

Giulia DEGNI (CPPM - AMU)

02/06/2026 12:00

Cosmic voids, the vast, underdense regions of the Universe, are emerging as powerful cosmological laboratories. They carry unique imprints of the growth of structure and the underlying physics driving cosmic acceleration. Among the most promising observables in this context is the void-galaxy cross-correlation function, which encodes both the geometry and dynamics of the cosmic web. In this...