Cooling of Neutron Stars admixed with light dark matter: A case study
M. Ángeles Pérez-García (Department of Fundamental Physics, Universidad de Salamanca, Salamanca, Spain); H. Grigorian (Laboratory of Information Technologies, JINR Dubna, Dubna, Russia, Computational Physics and IT Division, A.I. Alikhanyan National Science Laboratory, Armenia, Department for Theoretical Physics, Yerevan State University, Yerevan, Armenia); C. Albertus (Department of Fundamental Physics, Universidad de Salamanca, Salamanca, Spain)
; D. Barba (Department of Fundamental Physics, Universidad de Salamanca, Salamanca, Spain); J. Silk (Beecroft Institute of Particle Astrophysics and Cosmology, Department of Physics, University of Oxford, Oxford, UK, Institut d'Astrophysique, UMR 7095 CNRS, Université Pierre et Marie Curie, Paris, France, Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, USA)
Neutron Stars (NSs) are born as hot, lepton-rich objects that evolve according to the standard paradigm through subsequent stages where they radiate the excess of energy by emitting, first, neutrinos and, later on, photons. Current descriptions based on Standard Model calculations cannot fully explain all the existing cooling data series for the dozens of objects that have been reported. In this work, we consider the intriguing possibility that cooling NSs could be actually admixed with a fraction of light dark matter (LDM), χ. We focus on a particular case study assuming a generic light candidate with mass that undergoes self-annihilating reactions through pseudoscalar mediators producing neutrinos in the final state. We include one additional feature, allowing thermal conduction from LDM while inside the dark core. By performing simulations of the temperature evolution in the NS, we find that cooling patterns could be distorted by the presence of LDM and discuss these results in light of their observability.
