Fuzzy dark matter black holes and droplets

Abstract

We consider the possibility of having Dark Matter (DM) black holes motivated by the Einasto density profile. This generalizes both the noncommutative mini black hole model and allows DM to enter as the matter constituent which makes up the black hole. We show that it is possible to construct a black hole solution for each value of the Einasto index and for different values of the mass parameter, provided that the we work with the energy–momentum tensor of an anisotropic fluid. In particular, we achieve that by first considering the equation of state (EOS) $$p_r=-\rho $$ p r = - ρ . It turns out that the corresponding black hole solution exhibits a horizon structure similar to that of a Reissner–Nordström black hole and the central singularity is replaced by a regular de Sitter core. We also show that if the previous EOS is replaced by a nonlocal one, it is possible to construct a self-gravitating fuzzy DM droplet but also in this case, the radial pressure is negative. Finally, we contemplate scenarios of different dark matter black holes with moderate mass values which could have formed in galaxies. In particular, we probe the possibility whether such black holes could also be the central galactic objects.

Possible connection between dark matter and supermassive black holes

“…Similar conclusions as in [29] has been obtained from a theoretical point of view in [31] where the authors chose the Einasto DM profile motivated by similarities to the Gaussian distribution used in [32][33][34][35]. In the present work, we extended the study performed by [31] to the case of the Zhao DM profile [36] in order to not only understand the similarities and differences emerging from the latter and the Einasto profile but also to check the sensitivity of our results against the choice of different DM profiles. To this purpose, the Zhao profile is ideal because it encompasses several known DM profiles and it helps us to understand the role of DM in the central region of Milky Way.…”

“…Finally, [29] showed by a numerical simulation that if the central SMBH is replaced by an object made of darkinos, this model does not only reproduce the same kinematics for S-stars but also explain the G2 anomaly [30]. Similar conclusions as in [29] has been obtained from a theoretical point of view in [31] where the authors chose the Einasto DM profile motivated by similarities to the Gaussian distribution used in [32][33][34][35]. In the present work, we extended the study performed by [31] to the case of the Zhao DM profile [36] in order to not only understand the similarities and differences emerging from the latter and the Einasto profile but also to check the sensitivity of our results against the choice of different DM profiles.…”

“…To this purpose, the Zhao profile is ideal because it encompasses several known DM profiles and it helps us to understand the role of DM in the central region of Milky Way. We discover that similarly as in [31] fuzzy DM droplets and black holes with a horizon structure reminiscent of that encountered in a Reissner-Nordströom geometry or DM droplets can be constructed if the Zhao profile is coupled with an energy-momentum tensor for an anisotropic fluid and an EOS of the de Sitter-type, i.e. p r = −ρ.…”

“…p r = −ρ. Such an EOS has been widely used in the literature to model regular BHs [31,[37][38][39][40][41][42][43][44][45][46][47]. Furthermore, the BH solutions we found are regular at r = 0 while the analysis of the Hawking temperature for the Zhao inspired BH shows that the BH gets hotter as the horizon radius decreases.…”

Microscopic black holes as probes for quantum gravity

“…Note that the cases of ρ1 (𝑟; 𝑞) with 𝑞 = 1, 2, 3 have been studied before, 𝑞 = 1, 2 in the context of quantum spaces and 𝑞 = 3 in the context of vacuum polarisation and some others were studied in the context of dark matter halos [36]. The recoil velocity for each of those cases are shown in Figure 3, its value has been derived in [11]…”