10–13 Jun 2025
École de physique, Quai Ernest-Ansermet 24, 1205 Genève, Suisse
Europe/Zurich timezone

Modified gravity vs dark sector interactions: settling the dispute through the distortion of time

10 Jun 2025, 18:15
1h 45m
Main auditorium (École de physique, Quai Ernest-Ansermet 24, 1205 Genève, Suisse)

Main auditorium

École de physique, Quai Ernest-Ansermet 24, 1205 Genève, Suisse

Speaker

Sveva Castello (University of Geneva)

Description

Combining measurements of the growth rate of cosmic structure with gravitational lensing is considered as the optimal way to test for deviations from General Relativity on cosmological scales. In my poster, I will demonstrate that this standard method suffers from an important limitation, since models of dark matter with additional interactions can lead to exactly the same signatures as modified gravity in these two observables. Luckily, I will show that the coming generation of large-scale structure surveys, like the Square Kilometre Array, will allow us to break this degeneracy through measurements of the distortion of time.

Presentation materials