Speaker
Description
The objective of this study is to test the theoretical viability, thermodynamic consistency, and observational validity of interacting dark energy models in which energy is exchanged within the dark sector. Using analytical background dynamics, phase-space stability analysis, and thermodynamic entropy principles, all possible linear and nonlinear couplings are constrained. Theoretical considerations for physical viability favour energy transfer from dark energy to dark matter, with a phantom dark energy equation of state ($w < -1$) to ensure positive energy density, stability of perturbations, and the absence of future big rips. Based on observations, interacting dark energy models consistently outperform the $\Lambda$CDM model, with dynamically evolving equations of state and phantom-divide crossings. However, several problems remain, including unphysical negative energy density during reverse energy exchange, extreme parameter degeneracies, early-time perturbation instabilities, and future cosmic singularities.
Other Fields of Research (Track) for Abstract
Cosmology
| Nature of work | Theoretical |
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