A self-consistent single-fluid framework for neutron stars admixed with mirror dark matter
Abstract
We develop a self-consistent dark matter admix neutron star framework based on a contact vector current--current interaction that couples the chemical potentials of both sectors through mutual mean-field shifts, with the dark matter (DM) fraction FD = ND/NB fixed as a global input parameter. This formulation provides a physically motivated alternative to fixed-density prescriptions, allowing the local DM density to follow the baryonic matter (BM) density throughout the stellar interior. As an application, we consider a mirror-DM scenario with exact symmetry between the dark and visible sectors and investigate NS matter using the NL3ωρ, FSU2R, NL3, and DDME2 equations of state (EOSs). We find that the amount of DM introduced through FD weakens the binding of dense matter, reduces its incompressibility, and softens the EOS, while the DM--BM interaction governs the microscopic behavior of the DM in the dense BM medium. Consequently, DM increases the central density and compactness of NSs, lowers their maximum masses, and shifts the onset of the direct Urca process to higher stellar densities. As a consequence, the onset of rapid cooling is shifted to more massive stars for models with a stiff symmetry energy and to less massive stars for models with a soft symmetry energy, depending on the extra compactness that results from the DM admixture. These results demonstrate that mirror-DM admixtures modify both the microscopic composition and macroscopic structure of NSs, with potential implications for their thermal evolution and multimessenger observational signatures.
Versions
Related
- Finite-Temperature Axion-Admixed Neutron Stars in a Quarkyonic Crossover Framework
- Bayesian exploration of weakly interacting models of dark matter admixed neutron stars based on multi-density constraints
- Structure and astrophysical properties of dark energy admixed neutron stars
- Radii and Scaling Relations of Dark-Matter-Admixed Neutron Stars
- Two-Fluid Radial Stability of Dark-Matter-Admixed Compact Objects: Dark Compact Planets, Dark White Dwarfs, Dark Neutron Stars, and Dark Oysters
BibTeX
@misc{issifu2026selfconsistent,
title = {{A self-consistent single-fluid framework for neutron stars admixed with mirror dark matter}},
author = {Adamu Issifu and Constança Providência and Franciele M. da Silva and Débora P. Menezes and Tobias Frederico},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2607.00888},
eprint = {2607.00888},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.00888},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - A self-consistent single-fluid framework for neutron stars admixed with mirror dark matter
AU - Adamu Issifu
AU - Constança Providência
AU - Franciele M. da Silva
AU - Débora P. Menezes
AU - Tobias Frederico
PY - 2026
DA - 2026/08/28
PB - arXiv
DO - 10.48550/arxiv.2607.00888
UR - https://arxiv.org/abs/2607.00888
AB - We develop a self-consistent dark matter admix neutron star framework based on a contact vector current--current interaction that couples the chemical potentials of both sectors through mutual mean-field shifts, with the dark matter (DM) fraction F_D = N_D/N_B fixed as a global input parameter. This formulation provides a physically motivated alternative to fixed-density prescriptions, allowing the local DM density to follow the baryonic matter (BM) density throughout the stellar interior. As an application, we consider a mirror-DM scenario with exact symmetry between the dark and visible sectors and investigate NS matter using the NL3ωρ, FSU2R, NL3, and DDME2 equations of state (EOSs). We find that the amount of DM introduced through F_D weakens the binding of dense matter, reduces its incompressibility, and softens the EOS, while the DM--BM interaction governs the microscopic behavior of the DM in the dense BM medium. Consequently, DM increases the central density and compactness of NSs, lowers their maximum masses, and shifts the onset of the direct Urca process to higher stellar densities. As a consequence, the onset of rapid cooling is shifted to more massive stars for models with a stiff symmetry energy and to less massive stars for models with a soft symmetry energy, depending on the extra compactness that results from the DM admixture. These results demonstrate that mirror-DM admixtures modify both the microscopic composition and macroscopic structure of NSs, with potential implications for their thermal evolution and multimessenger observational signatures.
ER -