Asymmetric Dark Matter Imprint on Low-mass Main-sequence Stars in the Milky Way Nuclear Star Cluster

Abstract

In this work, we study the impact of asymmetric dark matter (ADM) on low-mass main-sequence stars in the Milky way's nuclear star cluster, where the dark matter (DM) density is expected to be orders of magnitude above what is found near the Sun (ρ DM 10 3 GeV cm −3 ). Using a modified stellar evolution code and considering a DM particle (m χ = 4 GeV) with a spin-dependent interaction cross section close to the limits allowed by direct detection, we found that the interactions of ADM with baryons in the star's core can have two separate effects on the evolution of these stars: a decrease in the hydrogen burning rate, extending the duration of the main-sequence of stars with M ∼ 1 M by a few Gyr; the suppression of the onset of convection in the core of stars with M 1.5M , and consequent quench of supply for the nuclear reactions. If we consider ρ DM > 10 3 GeV cm −3 (corresponding to the inner 5 pc of the Milky Way), stars lighter than the Sun will have a mainsequence life span comparable to the current age of the universe. Stars heavier than two solar masses are not sensitive to the DM particles considered here.

Neutron stars: new constraints on asymmetric dark matter

“…Such type of DM is usually called asymmetric dark matter (ADM).There is a large number of articles that have explored ADM in different astrophysical contexts. Examples are the studies of ADM in the Sun [13][14][15][16] and other stars [17,18]. This DM type is the subject of our study in this letter.…”

Delayed Detonation Thermonuclear Supernovae with an Extended Dark Matter Component

“…Ongoing studies have been focusing on different aspects of compact objects, including bosonic DM stars (Eby et al 2016;Lee et al 2021, in preparation), formation of neutron stars through the accretioninduced collapse of DM-admixed white dwarfs (WDs; Leung et al 2019;Zha et al 2019), tidal properties of DM-admixed neutron stars (Leung et al 2021, in preparation), thermalization of the WD core to produce a thermonuclear runaway (Bramante 2015;Acevedo & Bramante 2019;Janish et al 2019;Steigerwald et al 2019), and thermonuclear supernovae with point-mass DM cores (Leung et al 2015a). Other than compact objects, effects of DM admixture on stellar formation (Arun et al 2019) and evolution (Scott et al 2008;Freese et al 2016;Lopes & Lopes 2019) are actively investigated. In particular, the evolution of AGB stars is used to constrain the properties of axion-like particles (Dolan et al 2021).…”

Anisotropic Dark Matter Stars

“…There may exist DM stars (DMSs) [48,49] powered by WIMP DM annihilation [50,51]. In regions of high DM density, such as the Galactic center, the capture and annihilation of WIMP DM by stars has the potential to significantly alter their evolution [52][53][54][55]. In Reference [56] it was shown that WIMPs accreted onto neutron stars may provide a mechanism to seed strangelets in compact objects for WIMP masses above a few GeV.…”