6 papers
Observational constraints on Diffusion Cosmologies in Unimodular Gravity from DESI DR2
Gabriel Gomez, Guillermo Palma, Norman Cruz
Diffusion functions in unimodular gravity induce a dynamical effective cosmological constant, providing an appealing framework in light of recent DESI observations. In this work, w…
Unimodular Gravity with Arbitrary Diffusion Function: A Dynamical System Reconstruction Approach
Gabriel Gómez, Guillermo Palma, Norman Cruz
We investigate cosmological diffusion models in unimodular gravity within a dynamical systems reconstruction framework. By treating the logarithmic slope of the diffusion sector as…
Thermodynamic constraints and future singularities in Unimodular Gravity driven by phantom and non-phantom fluids
Norman Cruz, Samuel Lepe, Guillermo Palma +1
This work investigates future cosmological singularities in a flat FLRW universe filled with a single barotropic fluid, (), within the framework of unimodular gravity.…
Dissipative Unimodular Gravity: Linking Energy Diffusion to Bulk Viscosity as an Alternative to CDM under DESI DR2 Data
Norman Cruz, Esteban González, Guillermo Palma
In this paper, we perform a theoretical and observational study of the presence of viscosity in the Unimodular Gravity formalism, a pioneering approach that, to the best of our kno…
Non-linear causal bulk viscosity in Unified Dark Matter Cosmologies
Guillermo Palma, Gabriel Gomez
We propose a bulk viscous unified dark matter scenario based on a nonlinear extension of the full causal Israel-Stewart theory. This framework allows the viscous fluid to remain fa…
Viscous Unified Dark Matter Models Under Scrutiny: Uncovering Inconsistencies from Dynamical System Analysis
Guillermo Palma, Gabriel Gomez, Norman Cruz
Viscous unified dark matter models aim to describe the dark sector of the Universe, as the dark matter fluid itself gives rise to an accelerated expansion due to a negative bulk vi…