Modified gravity and cosmology

EN Saridakis, R Lazkoz, V Salzano, PV Moniz… - 2021 - Springer
The dawn of the twenty-first century came with very positive prospects for gravity, cosmology,
and astrophysics. Technological progress made it possible for cosmology to enter to its …

[HTML][HTML] Supercomputers against strong coupling in gravity with curvature and torsion

WEV Barker - The European Physical Journal C, 2023 - Springer
Many theories of gravity are spoiled by strongly coupled modes: the high computational cost
of Hamiltonian analysis can obstruct the identification of these modes. A computer algebra …

[HTML][HTML] Radiative corrections in metric-affine bumblebee model

A Delhom, JR Nascimento, GJ Olmo, AY Petrov… - Physics Letters B, 2022 - Elsevier
We consider the metric-affine formulation of bumblebee gravity, derive the field equations,
and show that the connection can be written as Levi-Civita of a disformally related metric in …

Parameterized nonrelativistic limit of stellar structure equations in Ricci-based gravity theories

GJ Olmo, D Rubiera-Garcia, A Wojnar - Physical Review D, 2021 - APS
We present the nonrelativistic limit of the stellar structure equations of Ricci-based gravities,
a family of metric-affine theories whose Lagrangian is built via contractions of the metric with …

Inflation with R (αβ) terms in the Palatini formulation

J Annala, S Räsänen - Journal of Cosmology and Astroparticle …, 2021 - iopscience.iop.org
We study inflation with the most general non-degenerate gravitational action that depends
on the symmetric part of the Ricci tensor coupled to a scalar field in the Palatini formulation …

[HTML][HTML] Born-Infeld gravity: Constraints from light-by-light scattering and an effective field theory perspective

JB Jiménez, A Delhom, GJ Olmo, E Orazi - Physics Letters B, 2021 - Elsevier
By using a novel technique that establishes a correspondence between general relativity
and metric-affine theories based on the Ricci tensor, we are able to set stringent constraints …

Compact objects in quadratic Palatini gravity generated by a free scalar field

RB Magalhães, LCB Crispino, GJ Olmo - Physical Review D, 2022 - APS
We study the correspondence that connects the space of solutions of general relativity (GR)
with that of Ricci-based gravity theories (RBGs) of the f (R, Q) type in the metric-affine …

Projective transformations in metric-affine and Weylian geometries

D Sauro, R Martini, O Zanusso - International Journal of Geometric …, 2023 - World Scientific
We discuss generalizations of the notions of projective transformations acting on affine
model of Riemann–Cartan and Riemann–Cartan–Weyl gravity which preserve the projective …

Some recent results on Ricci-based gravity theories

GJ Olmo, D Rubiera-Garcia - International Journal of Modern …, 2022 - World Scientific
In this paper, metric-affine theories in which the gravity Lagrangian is built using (projectively
invariant) contractions of the Ricci tensor with itself and with the metric (Ricci-based gravity …

Generating rotating spacetime in Ricci-based gravity: naked singularity as a black hole mimicker

WH Shao, CY Chen, P Chen - Journal of Cosmology and …, 2021 - iopscience.iop.org
Motivated by the lack of rotating solutions sourced by matter in General Relativity as well as
in modified gravity theories, we extend a recently discovered exact rotating solution of the …