Distinct observational signatures of dark matter in evolving neutron stars

by Adamu Issifu (Instituto Tecnologico de Aeronáutica, Brasil)

Wednesday 6 May 2026, 14:00 → 15:00 Portugal

Sala de Conferências (Departamento de Física FCTUC)

Dense astrophysical objects, such as neutron stars, have long served as probes of fundamental physics. The absence of signals in dark matter (DM) direct detection experiments has further motivated the search for DM signatures in these systems. In this work, we explore such signatures during the early protoneutron star (PNS) phase. Using a two-fluid formalism in which DM interacts with ordinary matter (OM) solely through gravity, we model the structural and thermal evolution of PNSs admixed with asymmetric DM, considering both fermionic and bosonic candidates. We find a clear and distinctive thermal signature of DM: a compact DM core heats the star by deepening the gravitational potential and compressing OM, whereas an extended DM halo provides additional support, leading to net cooling. This behavior contrasts with that of exotic baryons, which soften the equation of state and systematically reduce stellar temperatures. Furthermore, the nature of the DM–OM coupling plays a decisive role: gravitational coupling leads to heating, while nongravitational interactions, modeled via a Higgs portal as a single fluid, allow DM to act as a heat reservoir, inducing cooling. These contrasting thermal imprints provide a potentially observable discriminant of DM properties through combined multimessanger observations, including supernova neutrino emission and the thermal evolution of young neutron stars.