Oral comunication
T. B. Gonçalves, L. Atayde, N. Frusciante
Abstract
We study a Symmetric Teleparallel Gravity with a Lagrangian of Logarithmic form. The full model
leads to an accelerated Universe and for specific values of the free parameters the Hubble rate re-
duces to the well known DGP model, though the evolution of the gravitational potentials are differ-
ent. We consider different branches of the Logarithmic model, among which sDGP and nDGP. The
phenomenology of both the background and linear perturbations is discussed, including all the rel-
evant effects on Cosmic Microwave Background radiation (CMB) angular power spectrum, lensing
and matter power spectra. To this purpose, we modified the Einstein-Boltzmann code MGCAMB.
In some cases, it is possible to have a phenomenology such that the lensing auto-correlation power
spectrum is enhanced and the matter power spectrum is suppressed for the same choice of parame-
ters. These features are of interest in view of understanding the excess of lensing in CMB data and
the σ8 tension. In some cases it is possible to have a suppressed ISW tail which is a feature preferred
by CMB data;
Spanish and Portuguese Relativity Meeting (EREP 2024)
Coimbra, Portugal
2024 July
