Realistic neutron star constraints on bosonic asymmetric dark matter

Abstract

It has been argued that the existence of old neutron stars excludes the possibility of non-annihilating light bosonic dark matter, such as that arising in asymmetric dark matter scenarios. If non-annihilating dark matter is captured by neutron stars, the density will eventually become sufficient for black hole formation. However, the dynamics of collapse is highly sensitive to dark-matter self-interactions. Repulsive self-interactions, even if extremely weak, can prevent black hole formation. We argue that self-interactions will necessarily be present, and estimate their strength in representative models. We also consider co-annihilation of dark matter with nucleons, which arises naturally in many asymmetric dark matter models, and which again acts to prevent black hole formation. We demonstrate how the excluded region of the dark-matter parameter space shrinks as the strength of such interactions is increased, and conclude that neutron star observations do not exclude most realistic bosonic asymmetric dark matter models.Comment: v1: 14 pages, 4 figures; v2: references added, minor modifications; v3: matches published versio

Decaying asymmetric dark matter relaxes the AMS-Fermi tension

“…To end up this article, we would like to comment on constraints on the non-annihilating bosonic ADM. From some astrophysical objects such as the neutron star, it is can be constrained or even excluded for the light bosonic ADM [42] (but with exception [43]). However, heavy bosnic ADM has not been constrained yet [41].…”

Indirect detection of self-interacting asymmetric dark matter

“…The stability of neutron stars generally imposes stronger constraints on A hS [54][55][56][57] but these constraints do not apply to scalar dark matter with masses at the TeV scale or above [58]. We will not use A hS in our analysis; therefore, it can be set arbitrarily small.…”

Blocking the Hawking radiation

“…Observations of old compact stars have been used in order to impose constraints on specific types of (a)symmetric dark matter [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] or to predict new effects [17,18]. A set of the derived constraints is based on the fact that asymmetric dark matter can be trapped inside compact stars and under certain conditions, the WIMP population might collapse forming a black hole at the center of the star which eventually can consume it.…”