2025/09/20 by Araujo, L. F., Lugones, G., Lima, J. A. S. · 1 citation
#FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2509.16484
The impact of energy exchange among the relevant fluid components: baryonic matter, fermionic dark matter (DM), and dark energy (DE) on the internal structure of neutron stars is investigated. Using a representative DM mass mχ = 10 GeV and a barotropic DE relation, we add source terms Qi to the Tolman-Oppenheimer-Volkoff equations and examine three cases: (i) noninteracting fluids (Model I), (ii) fully interacting baryon plus DM and DM with DE fluids with optional DM self repulsion (Model II), and (iii) a unified dark sector coupled to baryons (Model III). Two effects dominate: softening by massive, pressure-poor DM, and additional softening/ and binding from DE with negative pressures. Model I isolates these baselines. In Model II, exchange terms self regulate, making the mass radius curves nearly independent of the coupling parameter α for nearly five orders of magnitude. Model III breaks this α degeneracy: a sizable vacuum fraction suppresses the baryonic pressure gradient, reducing both the maximum mass and radii, whereas a pure-DM core is less sensitive. We outline when dark interactions can leave observable, macroscopic imprints.