Revisiting constraints on asymmetric dark matter from collapse in white dwarf stars

Abstract

The runaway collapse phase of a small dark matter cluster inside a white dwarf star encompasses a reversible stage, where heat can be transferred back and forth between nuclear and dark matter. Induced nuclear burning phases are stable and early carbon depletion undermines previous claims of type Ia supernova ignition. Instead, mini black holes are formed at the center of the star that either evaporate or accrete stellar material until a macroscopic sub-Chandrasekhar-mass black hole is formed. In the latter case, a 0.1 to 1 second lasting electromagnetic transient signal can be detected upon ejection of the white dwarf's potential magnetic field. Binary systems that transmute to black holes and subsequently merge emit gravitational waves. Advanced LIGO should detect one such sub-Chandrasekhar binary black hole inspiral per year, while future Einstein telescope-like facilities will detect thousands per year. The effective spin parameter distribution is peaked at 0.2 and permits to disentangle from primordial sub-Chandrasekhar black holes. Such signatures are compatible with current direct detection constraints, as well as with neutron star constraints in the case of bosonic dark matter, even though they remain in conflict with the fermionic case for part of the parameter space.

Near- and sub-solar-mass naked singularities and black holes from transmutation of white dwarfs

“…Our proposed new channel to form such naked-singularities assumes the existence of asymmetric or non-self-annihilating PDM particles [29]. There are several proposed DM candidates and non-self-annihilating PDM particles are one of them (see figure 1 of [30] for details).…”

“…For example, our figure 2 clearly shows that even if we consider only the m χ < 100 TeV PDM particles, some WDs can be transmuted into BHs or naked singularities. Moreover, for non-self-annihilating PDM particles, [29] showed that an endoparasitic BH is formed inside a WD, and may accrete matter from the WD until a macroscopic BH is formed (although this paper does not consider naked singularities). In support to their claim, [29] argued that JCAP06(2024)007 the heat could be transferred between the nuclear matter and DM, nuclear burning phases could be stable and carbon could have been depleted early [29].…”

“…Moreover, for non-self-annihilating PDM particles, [29] showed that an endoparasitic BH is formed inside a WD, and may accrete matter from the WD until a macroscopic BH is formed (although this paper does not consider naked singularities). In support to their claim, [29] argued that JCAP06(2024)007 the heat could be transferred between the nuclear matter and DM, nuclear burning phases could be stable and carbon could have been depleted early [29]. Support for the formation and growth of a BH can also be found elsewhere (e.g., page 20 of [70] and references therein; page 5 of [3]).…”

Could compact stars in globular clusters constrain dark matter?

“…This idea has been investigated in the context of DM in primordial black holes depositing energy in WDs via dynamical friction [104], non-annihilating particle DM captured by the WD depositing gravitational potential energy via nucleon scattering as it collapses in the WD [104,105] (though see ref. [106]), heavier-than-10 16 GeV DM depositing energy via annihilations, decays or nuclear scattering [107], and energy deposition from rapid Hawking radiation emitted by black holes formed in the interior of WDs via DM collapse [108,109].…”

Ignition of Carbon Burning from Nuclear Fission in Compact Stars

“…Recently, we proposed a new SN Ia mechanism that involves a nuclear fission chain reaction igniting thermonuclear carbon burning in an isolated WD (Horowitz & Caplan 2021a, 2021b. Alternative mechanisms to ignite isolated WD include dark matter interactions (Bramante 2015;Steigerwald et al 2022) or pycnonuclear fusion of impurities (Chiosi et al 2015).…”