G. Poulot, E. M. Teixeira, C. van de Bruck, N. J. Nunes
Abstract
We propose a new model of scalar field dark matter interacting with dark energy. Adopting a fluid description of the dark matter field in the regime of rapid oscillations, we find that the equation of state for dark matter is non-zero and even becomes increasingly negative at late times during dark energy domination. Furthermore, the speed of sound of dark matter is non-vanishing at all length scales, and a non-adiabatic pressure contribution arises. The results indicate that there are still unexplored possible interactions within the dark sector that lead to novel background effects and can impact structure formation processes.
Keywords
dark matter theory / dark energy theory
Journal of Cosmology and Astroparticle Physics
Volume 2025, Issue 005, Page 24
2025 November
