Cosmic Rhythms

Session

Dark energy and modified gravity

8 Sept 2026, 14:00

Auditório Ministro João Alberto Lins e Barros (CBPF)

75. Gravity in the Era of Stage IV LSS Surveys

Alessandra Silvestri

08/09/2026, 14:00

Oral Talk

Stage IV Large Scale Structure Surveys are ushering in a new era of precision cosmology!
In this talk, I will explore the effort to test gravity on cosmological scales, highlighting the theoretical advancements aimed at constructing an optimal framework. I will also touch on the synergy with gravitational wave surveys. Additionally, I will provide a detailed review of recent findings based on...

27. Constraining dark sector models with galaxy clustering and the CMB

Francesco Verdiani (SISSA, Trieste), Francesco Verdiani (SISSA, Trieste)

08/09/2026, 16:30

Oral Talk

In several cosmological scenarios, such as massive neutrinos or ultra-light axions, the dark matter comprises a warm component alongside the cold one. This modifies the late-time evolution of the dark sector, thus making galaxy clustering an ideal probe of these models. We study the non-linear evolution of perturbations in this context, and build an EFTofLSS-based model that allows for a...

79. Microphysics of Dynamical Dark Energy

João Victor Silva Rebouças

08/09/2026, 16:45

Theory & Fundamental Physics

Oral Talk

Hints of dynamical dark energy have recently emerged from distance measurements from type Ia supernovae and galaxies through the Baryonic Acoustic Oscillation feature, challenging the current paradigm in cosmology. This new perspective has encouraged the proposal of physical mechanisms able to consistently explain the observations, such as modified gravity and interactions between dark matter...

19. The distribution and nature of dark matter

Richard Massey (Durham University)

08/09/2026, 17:00

Oral Talk

We combine ESA's Euclid mission and NASA's SuperBIT mission to test the hypothesis that dark matter particles interact with each other, through forces besides gravity. The hypothesis predicts that dark matter’s trajectory through collisions will deviate from the purely gravitational trajectories followed by stars. To test it, we have observed astrophysical versions of dark matter colliders...

93. A New Public Framework for Testing Gravity with Full-Shape Galaxy Clustering

Cristhian Garcia Quintero (Center for Astrophysics Harvard-Smithsonian), Rafaela Gsponer (EPFL)

08/09/2026, 17:15

Oral Talk

Signatures from departures away from the standard model of cosmology justify the search for extended models of gravity. The full shape data from DESI DR2 will provide enhanced precision to test the growth of structure, valuable to constraints extensions beyond the standard model of gravity. We develop a new EFT pipeline for phenomenological tests of gravity, providing a framework for...

35. What drives a high growth index? Insights from dark energy and varying G.

Ronaldo Batista (Federal University of Rio Grande do Norte)

08/09/2026, 17:30

Oral Talk

Recent observational determinations of the cosmological growth index suggest values significantly higher than the standard ΛCDM prediction. I will discuss whether two cosmological scenarios can account for such high values. First, I will show that both homogeneous and clustering dark energy models face serious difficulties in producing elevated growth index values (arXiv:2411.00963). Next, I...

60. Non-linear matter power spectrum for interacting dark sector models

Rodrigo von Marttens (Federal University of Bahia)

08/09/2026, 17:45

Oral Talk

Interacting dark sector (IDS) models provide a commonly explored extension of the standard $\Lambda$CDM cosmology, allowing for non-gravitational energy--momentum exchange between cold dark matter (CDM) and dark energy (DE). Although such models can reproduce similar background expansion history as dynamical DE models, their impact on the growth of cosmic structures is fundamentally different...