Conveners
Session 3 - Modified Gravity & Dark Energy
- Session convener: Filipe Mena
We introduce new simple analytical approximations for quintessence solutions covering both tracking (asymptotically inverse power-law potentials) and thawing slow-roll models. From an observational perspective the remarkable accuracy of the approximations makes numerical calculations superfluous when assessing observational constraints. We will then discuss ongoing work on generalisations for...
The wide range of modified gravity theories proposed to address the limitations of General Relativity (GR) presents a challenge in distinguishing between them. In particular, the Geometric Trinity of Gravity - comprising General Relativity, based on curvature; Teleparallel Gravity, which relies on torsion and Symmetric Teleparallel Gravity, which is formulated in terms of nonmetricity- are...
The canonical cosmological model to explain the recent acceleration of the universe relies on a cosmological constant, and most dynamical dark energy and modified gravity model alternatives are based on scalar fields. Still, further alternatives are possible. One of these involves vector fields: under certain conditions, they can lead to accelerating universes while preserving large-scale...
The elusive cosmological redshift drift — predicted by General Relativity as a direct signature of the universe's accelerated expansion — remains one of the most ambitious goals in observational cosmology. In this study, we take the first steps toward detecting this effect using the Lyman-α forest of bright quasars as tracers of the expanding cosmos. Focusing on the brightest quasar,...
There has been recent interest in the cosmological consequences of energy-momentum-powered-gravity models, in which the matter side of Einstein’s equations includes a term proportional to some power, n, of the energy-momentum tensor, in addition to the canonical linear term. Previous works have suggested that these models can lead to a recent accelerating universe without a cosmological...
We analyse the late-time cosmological effects of a modified theory of gravity with a non-minimal coupling between curvature and matter. By evolving the cosmological parameters that match the cosmic microwave background data until their values from direct late-time measurements, we will show how to obtain an agreement between different experimental methods without disrupting their individual...
This work explores the viability of Hyperconical Modified Gravity (HMG) as a relativistic alternative to the Modified Newtonian Dynamics (MOND) in explaining the dynamics of galaxy clusters, radial accelerations and galaxy rotation curves. By using five datasets (including high-resolution X-ray data and weak-lensing observations), we test HMG's predictions for hydrostatic equilibrium in galaxy...
