Conveners
Session 4 - Modified Gravity & Dark Energy
- Session convener: Artur Alho
The accelerated expansion of the Universe is canonically attributed to the Dark Energy (DE), encapsulated in the Lambda factor in the Einstein field equations of gravity, but its nature is still not understood. While observations supply strong evidence in favor of the standard model of cosmology Lambda-CDM, a plethora of different modified gravity models (MG) can still arise and describe...
The next generation of galaxy surveys will provide unprecedented data, leading to accurate tests of gravity on cosmological scales. To fully exploit the nonlinear information encoded in the large-scale structure of the Universe, we propose to leverage cutting-edge deep learning algorithms, such as diffusion models, to efficiently generate 3D density fields conditioned on cosmological...
The $f(\mathcal{G},T)$ theory of gravity is recast in terms of the $\phi$ and $\psi$ fields within the scalar-tensor formulation, where $\mathcal{G}$ is the Gauss-Bonnet term and $T$ denotes the trace of the energy-momentum tensor. The general aspects of the introduced reformulation are discussed and the reconstruction of the cosmological scenarios is presented, focusing on the so-called...
I will present expansions of the metric and its derivative near a conformal gauge singularity (also known as isotropic singularities) for Bianchi I symmetric massless solutions of the Einstein-Vlasov and Einstein-Boltzmann system with a magnetic field. We will discuss how this can be related to our universe. This is work in collaboration with Ho Lee, John Stalker and Paul Tod.
In the quest to understand the accelerated expansion of the universe, f(Q) gravity offers a promising alternative to General Relativity (GR) by incorporating non-metricity into the gravitational framework. Unlike GR, which relies on spacetime curvature, f(Q) gravity modifies the Einstein-Hilbert action by replacing the Ricci scalar R with a function f(Q), where Q represents the non-metricity...
